v2.2.0

学生登录后只显示本人座位对应的考场，同时修复混排考场可能带出其他课程的问题。[筛选逻辑 (line 561)](E:/jiaowu/src/Jiaowu.Api/Infrastructure/Timetables/TimetableDataService.cs:561)
多考场卡片提示学生登录查看本人考场及监考教师。[前端展示 (line 1122)](E:/jiaowu/web/src/views/TimetableView.vue:1122)
教室课表、监考教师课表仍按具体考场显示，不受合并影响。
已增加班级合并和学生精准考场回归测试。[测试 (line 183)](E:/jiaowu/tests/Jiaowu.Api.Tests/ExamArrangementServiceTests.cs:183)

.env.docker.example

@@ -8,9 +8,16 @@ MYSQL_USER=jiaowu
 MYSQL_PASSWORD=
 MYSQL_ROOT_PASSWORD=
 
+RABBITMQ_USER=jiaowu
+RABBITMQ_PASSWORD=
+BACKGROUND_JOB_AUTOMATIC_SCHEDULE_CONCURRENCY=1
+BACKGROUND_JOB_SCHEDULE_PUBLISH_CONCURRENCY=1
+BACKGROUND_JOB_MAKEUP_EXAM_AUTO_CONCURRENCY=1
+
 JWT_KEY=
 ALLOWED_HOSTS=localhost
 CORS_ORIGIN=http://localhost:8080
+OFFICIAL_DOCUMENTS_PUBLIC_BASE_URL=http://localhost:8080
 
 # 仅首次创建演示管理员时使用；演示数据成功写入后删除下面三行。
 SEED_ADMIN_USERNAME=demo-admin

.env.example

@@ -6,6 +6,63 @@ Database__Provider=MySql
 Database__ApplyMigrationsOnStartup=false
 Database__CommandTimeoutSeconds=30
 ConnectionStrings__MySql="Server=db.example.edu.cn;Port=3306;Database=jiaowu;User=APP_USER;Password=REPLACE_WITH_A_STRONG_PASSWORD;SslMode=VerifyFull;SslCa=/etc/jiaowu/mysql-ca.pem;"
+# 仅供备份与隔离恢复演练使用。该账号需要读取业务库，并仅能创建/删除
+# jiaowu_restore_drill_* 临时库；不要在此复用日常业务账号。
+# ConnectionStrings__OperationsMySql="Server=db.example.edu.cn;Port=3306;Database=jiaowu;User=OPS_USER;Password=REPLACE_WITH_A_STRONG_PASSWORD;SslMode=VerifyFull;SslCa=/etc/jiaowu/mysql-ca.pem;"
+# Redis 是可选加速器；留空时应用仅使用进程内缓存。
+# ConnectionStrings__Redis="redis.example.edu.cn:6380,user=jiaowu,password=REPLACE_WITH_A_STRONG_PASSWORD,ssl=true,abortConnect=false"
+
+# 单机可继续使用 InMemory；多实例生产部署建议启用 RabbitMQ。
+BackgroundJobs__Transport=InMemory
+BackgroundJobs__AutomaticScheduleConcurrency=1
+BackgroundJobs__SchedulePublishConcurrency=1
+BackgroundJobs__MakeupExamAutoConcurrency=1
+BackgroundJobs__ExamArrangementConcurrency=1
+# RabbitMq__HostName=rabbitmq.example.edu.cn
+# RabbitMq__Port=5671
+# RabbitMq__UserName=jiaowu
+# RabbitMq__Password=REPLACE_WITH_A_STRONG_PASSWORD
+# RabbitMq__VirtualHost=/jiaowu
+# RabbitMq__UseTls=true
+# RabbitMq__TlsServerName=rabbitmq.example.edu.cn
+
+Cache__Enabled=true
+Cache__KeyPrefix=jiaowu:v1
+Cache__ReferenceExpirationMinutes=30
+Cache__ReferenceLocalExpirationSeconds=120
+Cache__TimetableExpirationMinutes=10
+Cache__TimetableLocalExpirationSeconds=30
+Cache__AnalyticsExpirationMinutes=3
+Cache__AnalyticsLocalExpirationSeconds=30
+Cache__MaximumPayloadKilobytes=2048
+
+# OpenTelemetry 默认收集 HTTP、运行时和数据库指标；配置 OTLP 地址后才会外发。
+Observability__Enabled=true
+Observability__ServiceName=jiaowu-api
+Observability__SlowQueryThresholdMilliseconds=500
+# 默认不记录完整 SQL，避免日志或追踪系统接触业务数据。
+Observability__IncludeSqlText=false
+Observability__MaximumSqlTextLength=2000
+# OTEL_EXPORTER_OTLP_ENDPOINT=https://otel-collector.example.edu.cn:4317
+# OTEL_EXPORTER_OTLP_HEADERS=Authorization=Bearer%20REPLACE_WITH_TOKEN
+
+# 系统内“运维与审计 → 系统性能”从 Prometheus 只读查询汇总指标。
+PerformanceReporting__Enabled=false
+# PerformanceReporting__PrometheusBaseUrl=https://prometheus.example.edu.cn/
+# PerformanceReporting__BearerToken=REPLACE_WITH_READ_ONLY_TOKEN
+# PerformanceReporting__GrafanaBaseUrl=https://grafana.example.edu.cn/
+PerformanceReporting__CacheSeconds=30
+PerformanceReporting__TimeoutSeconds=10
+
+# 运维控制台备份目录必须位于持久化、仅服务账号可写的位置。
+Operations__BackupDirectory=/var/lib/jiaowu/backups
+Operations__BackupWarningHours=24
+Operations__ToolTimeoutMinutes=30
+Operations__MySqlDumpPath=mysqldump
+Operations__MySqlClientPath=mysql
+# 按实际客户端补充 TLS 参数；Oracle MySQL 客户端示例：
+# Operations__MySqlAdditionalArguments__0=--ssl-mode=VERIFY_IDENTITY
+# Operations__MySqlAdditionalArguments__1=--ssl-ca=/etc/jiaowu/mysql-ca.pem
 
 Jwt__Issuer=Jiaowu.Api
 Jwt__Audience=Jiaowu.Web
@@ -14,6 +71,17 @@ Jwt__ExpireMinutes=60
 
 AllowedHosts=jiaowu.example.edu.cn
 Cors__Origins__0=https://jiaowu.example.edu.cn
+Cors__Origins__1=capacitor://localhost
+Cors__Origins__2=https://localhost
+Cors__Origins__3=http://localhost
+
+# 二维码使用的公网根地址；反向代理部署时必须填写最终 HTTPS 地址。
+OfficialDocuments__InstitutionName=明序大学
+OfficialDocuments__IssuingOffice=教务处
+OfficialDocuments__DocumentNumberPrefix=MXU
+OfficialDocuments__PublicBaseUrl=https://jiaowu.example.edu.cn
+# 默认使用系统中文字体；仅在自定义字体部署时填写绝对路径。
+# OfficialDocuments__FontPath=/usr/share/fonts/noto/NotoSansCJK-Regular.ttc
 
 # 仅首次创建管理员时临时取消注释，创建成功后立即删除。
 # SeedAdmin__UserName=admin

.gitignore

@@ -17,3 +17,4 @@ src/Jiaowu.Api/wwwroot/
 !.env.example
 !.env.docker.example
 certs/
+publish/

Dockerfile

@@ -30,10 +30,14 @@ FROM mcr.microsoft.com/dotnet/aspnet:10.0-alpine AS final
 WORKDIR /app
 ENV ASPNETCORE_ENVIRONMENT=Production \
     ASPNETCORE_HTTP_PORTS=8080 \
-    DOTNET_EnableDiagnostics=0
+    DOTNET_EnableDiagnostics=0 \
+    Operations__BackupDirectory=/var/lib/jiaowu/backups \
+    Operations__MySqlDumpPath=mariadb-dump \
+    Operations__MySqlClientPath=mariadb
 EXPOSE 8080
 COPY --from=build /app/publish/ ./
 ARG UID=10001
+RUN apk add --no-cache font-noto-cjk mariadb-client
 RUN adduser \
     --disabled-password \
     --gecos "" \
@@ -42,5 +46,9 @@ RUN adduser \
     --no-create-home \
     --uid "${UID}" \
     appuser
+RUN mkdir -p /var/lib/jiaowu/backups \
+    && chown appuser:appuser /var/lib/jiaowu/backups \
+    && chmod 700 /var/lib/jiaowu/backups
+VOLUME ["/var/lib/jiaowu/backups"]
 USER appuser
 ENTRYPOINT ["dotnet", "Jiaowu.Api.dll"]

README.md

@@ -2,7 +2,9 @@
 
 面向普通高校的教务管理系统。后端使用 ASP.NET Core 10、EF Core 10，前端使用 Vue 3、TypeScript 和 Element Plus。
 
-当前已实现系统登录与角色权限、基础数据、用户管理、教师档案、学生档案、课程库、培养方案、教学任务、排课课表、学生选课、成绩管理、考试考场、学籍异动、毕业审核、学位授予、毕业离校和首页统计。人员及课程列表支持组合筛选、服务端分页和完整增删改查；培养方案支持课程模块、专业年级版本、复制新版本、发布与旧版本归档，已发布版本可继续维护名称、学分说明和课程结构，适用专业、入学年级及版本号保持锁定；教学任务支持学期课程开设、多教师、合班、容量校验、发布与结课，公共课由校级教务负责、专业必修/专业选修/实践课下放课程所属学院管理，并支持教师按学期申报授课科目、学院审核授课资格、公共课按若干行政班合并教学班，以及在审核通过的教师池中随机均衡分配后批量生成草稿；排课支持学期作息维护、单双周与周次节次、课程可用时间、校区/教学楼/指定教室约束、不占用教室课程、教室容量、教师/行政班/教室冲突校验、自动生成、手工微调和版本化发布；选课支持批次时间窗、投放范围、容量与学分上限、重复课程与课表冲突校验、退课截止时间和实时教学班名单；成绩管理支持分项比例、批量录入、特殊考试状态、自动总评与绩点、教师提交、学院审核、校级发布和学生成绩单；考试管理支持考试计划、场次、考场容量、监考教师、考生名单以及考场/监考/学生时间冲突校验；学籍异动支持休学、复学、退学申请，辅导员、学院、学校三级顺序审核，学生撤回，以及最终审批后自动同步学籍状态；毕业审核按入学年级匹配已发布培养方案，以正式成绩计算总学分、必修通过和未解决不及格课程，支持学院范围查看、人工复核、校级锁定发布和学生结果查询；学位授予以已发布毕业资格为来源，按正式成绩加权平均绩点生成规则结论，支持学院人工复核、校级发布锁定和学生结果查询；毕业离校支持自定义事项与责任部门，按校级、学院、辅导员角色分工办理，强制数据范围校验，学生进度查询，以及必办事项全部完成后的批次锁定。
+官方电子凭证支持学生自助申请和教务代签，由服务端生成成绩单与学籍状态证明 PDF，并提供唯一凭证编号、二维码公开验真、下载记录、失效和重签；生产部署应通过 `OfficialDocuments__PublicBaseUrl` 配置二维码使用的最终 HTTPS 根地址。
+
+当前已实现系统登录与角色权限、基础数据、用户管理、教师档案、学生档案、课程库、培养方案、教学任务、排课课表、学生选课、成绩管理、考试考场、学籍异动、毕业审核、学位授予、毕业离校和首页统计。人员及课程列表支持组合筛选、服务端分页和完整增删改查；培养方案支持课程模块、专业年级版本、复制新版本、发布与旧版本归档，已发布版本可继续维护名称、学分说明和课程结构，适用专业、入学年级及版本号保持锁定；教学任务支持学期课程开设、多教师、合班、容量校验、发布与结课，公共课由校级教务负责、专业必修/专业选修/实践课下放课程所属学院管理，并支持教师按学期申报授课科目、学院审核授课资格、公共课按若干行政班合并教学班，以及在审核通过的教师池中随机均衡分配后批量生成草稿；排课支持学期作息维护、单双周与周次节次、课程可用时间、校区/教学楼/指定教室约束、不占用教室课程、教室容量、教师/行政班/教室冲突校验、自动生成、手工微调和版本化发布；教师和学生可启用个人教学日历订阅，将固定课程、考试/监考、补考及灵活课程提醒同步到支持 iCalendar 的客户端，并可重置或停用订阅地址；选课支持批次时间窗、投放范围、容量与学分上限、重复课程与课表冲突校验、退课截止时间、满员候补、顺位查询、退课后资格复核与自动递补，以及正式名单和候补队列管理；成绩管理支持分项比例、批量录入、特殊考试状态、自动总评与绩点、教师提交、学院审核、校级发布和学生成绩单；考试管理支持考试计划、场次、考场容量、监考教师、考生名单以及考场/监考/学生时间冲突校验；学籍异动支持休学、复学、退学申请，辅导员、学院、学校三级顺序审核，学生撤回，以及最终审批后自动同步学籍状态；毕业审核按入学年级匹配已发布培养方案，以正式成绩计算总学分、必修通过和未解决不及格课程，支持学院范围查看、人工复核、校级锁定发布和学生结果查询；学位授予以已发布毕业资格为来源，按正式成绩加权平均绩点生成规则结论，支持学院人工复核、校级发布锁定和学生结果查询；毕业离校支持自定义事项与责任部门，按校级、学院、辅导员角色分工办理，强制数据范围校验，学生进度查询，以及必办事项全部完成后的批次锁定。
 
 课程库支持下载标准模板后批量导入 `.xlsx`，按课程编码新增或更新，并在整批校验失败时不写入任何课程；授课资格既支持教师申报后审核，也支持学院在本院教师范围内直接分配；学生可在“我的培养方案”中查看本人适用的已发布方案，并按已完成、在读、重修中、未通过、待完成和未修读状态核对课程与学分进度。
 
@@ -45,6 +47,68 @@ dotnet run --project src/Jiaowu.Api
 
 访问 `http://localhost:5255`。`/api` 和静态页面由同一个 ASP.NET Core 服务提供，`/base-data` 等前端路由刷新时也会回退到 `index.html`。
 
+## Capacitor Android App
+
+`web/.env.capacitor` 配置 App 使用的 HTTPS API 与公开站点地址。生成或更新
+Android 工程前先构建并同步原生插件：
+
+```powershell
+Set-Location web
+npm ci
+npm run build:capacitor
+npm run cap:sync
+npm run cap:open:android
+```
+
+学生在 App 的“我的考勤”中可调用原生相机扫描教师展示的签到二维码；二维码由服务端
+签名、每 10 秒刷新并在 20 秒后失效，扫码后先显示课程和签到时限，仍需学生确认才
+提交。教师可直接在手机 App 发起定位签到，以教师手机的原生精确位置作为签到点；
+教室电脑没有定位模块时不影响该流程。服务端校验课程名单、签到时间、距离和定位精度，
+并记录签到设备摘要、IP、失败次数和异常频率，供任课教师在考勤明细中复核。Android
+最低版本为 API 26；相机和精确位置权限均按需申请。
+
+### App 前端热更新
+
+App 内置自建 OTA 更新器。它只更新 `dist` 中的 HTML、JavaScript、CSS 和静态资源；
+新增或升级 Capacitor 插件、修改原生权限、Android/iOS 工程或原生版本号时，仍必须
+重新构建并安装 App。首次启用更新器也需要发布一次包含更新插件的新 App，之后普通
+前端修复不再需要重新打包。
+
+生成更新 ZIP：
+
+```powershell
+Set-Location web
+npm ci
+npm run ota:package -- --version 1.0.1
+```
+
+ZIP 会生成到 `.artifacts/app-updates`，根目录直接包含 `index.html`。使用
+SuperAdmin 进入“运维与审计 → App 前端热更新”，上传 ZIP，填写目标平台、通道和
+兼容的原生版本后先保存为草稿，再执行发布。当前 Android 工程的 `versionName` 为
+`1.0`，因此对应更新包的“兼容原生版本”应填写 `1.0`。
+
+App 启动后向 `/api/app-updates/latest` 检查版本，在后台下载并校验服务端提供的
+SHA-256，下次启动时切换。新资源若未能成功启动，原生更新器会自动回滚。再次发布
+已归档版本即可回滚正式通道；不同原生版本、Android/iOS、测试/正式通道彼此隔离。
+更新版本元数据和 ZIP 保存在数据库中，部署新服务端版本前必须先执行
+`--migrate-only`。
+
+### Android 开屏、快捷入口与桌面组件
+
+Android App 在系统静态启动页之后显示智能问候：优先使用当前登录姓名和春节、端午、
+中秋、国庆等节日文案，其次按早上、中午、下午和晚上展示问候；轻触可立即跳过，并
+遵守系统“减少动画”设置。
+
+长按 App 图标提供“我的课表、考试安排、课堂签到、消息中心”四个快捷入口。“课堂
+签到”会按当前角色将学生带到扫码/定位签到，将教师带到发起签到。桌面组件提供“今日
+课表”和“近期考试”，展示 App 最近一次成功加载并安全写入 Android 本地缓存的数据；
+退出账号时会清空组件，跨日且尚未打开 App 刷新时不会继续展示过期的今日课表。
+
+原生 Java、清单和组件资源模板保存在 `web/native/android`。每次运行
+`npm run cap:sync` 后，`configure-capacitor.mjs` 会把模板同步到被 Git 忽略的
+`web/android` 生成目录。上述能力涉及 Android 原生代码，首次加入或以后修改时必须
+重新构建 App，不能通过前端 OTA 单独下发。
+
 ## MySQL 8.4 生产部署
 
 非 Development 环境只允许使用 MySQL。构建发布包与数据库配置相互独立：
@@ -99,6 +163,12 @@ sudo chown -R root:jiaowu /opt/jiaowu
 sudo chmod 0750 /opt/jiaowu
 sudo chmod 0750 /opt/jiaowu/Jiaowu.Api
 sudo chmod 0640 /opt/jiaowu/.env
+sudo install -d \
+  --owner=jiaowu \
+  --group=jiaowu \
+  --mode=0700 \
+  /var/lib/jiaowu/backups
+sudo apt-get install default-mysql-client
 ```
 
 如果账号已存在，`useradd` 会报错，可以跳过该命令。RHEL 系发行版的 `nologin` 通常
@@ -219,6 +289,151 @@ SQLite 只用于本地开发：新库通过 `EnsureCreated` 建立，已有开
 
 - `/health/live`：只检查进程存活。
 - `/health`、`/health/ready`：实际检查数据库连接，失败时返回 HTTP 503。
+- `/health/cache`：检查可选 Redis；未配置 Redis 时返回 `disabled`，Redis
+  故障不会影响数据库就绪探针。
+- `/health/messaging`：检查后台任务传输；单机内存队列返回 `memory`，启用
+  RabbitMQ 时实际检查代理连接，同时返回各 Outbox 状态的积压数、过期租约数和
+  最老未完成任务的等待时间。
+
+### 查询缓存与 Redis
+
+应用使用 HybridCache 统一管理进程内一级缓存和可选 Redis 二级缓存。目前缓存范围为
+学生激活/基础数据选项、匿名可访问的已发布课表、仪表盘以及统计分析摘要。统计缓存键
+包含有效数据范围、学院和规范化筛选条件，避免跨学院复用；统计 Excel 导出仍实时查询。
+选课容量、成绩写入、考勤、审批、通知未读数、权限和后台任务状态仍直接以 MySQL 为准。
+
+不配置 `ConnectionStrings__Redis` 时，开发和单机部署仍使用进程内缓存，不要求安装
+Redis。生产环境使用 Redis 时，通过环境变量配置连接串，例如：
+
+```text
+ConnectionStrings__Redis=redis.internal:6380,user=jiaowu,password=REPLACE_ME,ssl=true,abortConnect=false
+```
+
+仪表盘和统计摘要默认在 Redis 中缓存 3 分钟、进程内缓存 30 秒，可分别通过
+`Cache__AnalyticsExpirationMinutes` 和 `Cache__AnalyticsLocalExpirationSeconds`
+调整。该类汇总采用短 TTL 控制数据新鲜度，不要求每个业务写入点同步清理缓存。
+
+Redis 只作为可丢弃的查询缓存。连接失败时应用回源数据库，普通启动和
+`/health/ready` 不依赖 Redis；可以单独检查 `/health/cache`。缓存键自动包含运行环境，
+同一 Redis 可以安全承载 Development、Staging 和 Production，但生产环境仍建议使用
+独立实例、私有网络、ACL 和 TLS。
+
+`compose.example.yml` 包含不暴露宿主机端口的 Redis 服务，限制为 256 MB 并使用
+`allkeys-lfu` 淘汰策略，不启用持久化。`compose.app.example.yml` 不创建 Redis；
+如需连接外部 Redis，在 `.env` 中配置上述连接串即可。
+
+### OpenTelemetry 与慢查询定位
+
+应用已接入 OpenTelemetry 的 ASP.NET Core、HttpClient、.NET Runtime 指标，并通过
+`Jiaowu.Api.Database` ActivitySource 和 Meter 记录 EF Core 数据库命令。配置
+`OTEL_EXPORTER_OTLP_ENDPOINT` 后才启动 OpenTelemetry SDK 并向 OTLP Collector 外发；
+未配置时不会创建无处消费的请求 Span，也不会尝试连接本地 Collector，结构化慢查询日志
+仍然有效。
+
+```text
+Observability__Enabled=true
+Observability__ServiceName=jiaowu-api
+Observability__SlowQueryThresholdMilliseconds=500
+OTEL_EXPORTER_OTLP_ENDPOINT=https://otel-collector.example.edu.cn:4317
+```
+
+数据库指标包括 `jiaowu.db.command.duration`、`jiaowu.db.command.slow` 和
+`jiaowu.db.command.failed`。为关键 EF 查询添加 `TagWith("模块.查询名")` 后，日志和
+追踪会直接显示该稳定名称；无标签查询只显示操作类型和 SQL 模板哈希。默认
+`Observability__IncludeSqlText=false`，不会把 SQL、参数值或连接串发送到日志和追踪
+系统。仅在受控诊断窗口内临时启用完整 SQL 模板，并限制 Collector 权限与保留时间。
+
+应用侧阈值用于关联接口、TraceId 和查询名称；生产 MySQL 还应由数据库管理员启用慢查询
+日志，并将 `long_query_time` 设为与应用阈值一致。先按查询哈希/标签汇总高频慢查询，再
+对脱敏后的 `SELECT` 在测试库或只读副本执行 `EXPLAIN ANALYZE`，根据实际扫描行数和循环
+次数决定是否补组合索引或改写投影。`EXPLAIN ANALYZE` 会真实执行语句，不能直接用于生产
+写操作。参考 [MySQL 慢查询日志](https://dev.mysql.com/doc/refman/8.0/en/slow-query-log.html)
+和 [MySQL 8.4 EXPLAIN](https://dev.mysql.com/doc/refman/8.4/en/explain.html)。
+
+OpenTelemetry Collector 将指标写入 Prometheus 后，超级管理员可直接在“组织与权限 →
+运维与审计 → 系统性能”查看请求量、5xx 比例、HTTP/数据库 P95、慢查询趋势，以及最慢
+接口和数据库查询排行。报表由 API 使用固定 PromQL 只读查询 Prometheus，浏览器不会
+接触 Prometheus 地址或令牌；结果默认缓存 30 秒。原始 Trace 和更长时间范围仍建议在
+Grafana 中下钻，配置其地址后页面会显示跳转入口。
+
+```text
+PerformanceReporting__Enabled=true
+PerformanceReporting__PrometheusBaseUrl=https://prometheus.example.edu.cn/
+PerformanceReporting__BearerToken=REPLACE_WITH_READ_ONLY_TOKEN
+PerformanceReporting__GrafanaBaseUrl=https://grafana.example.edu.cn/
+PerformanceReporting__CacheSeconds=30
+PerformanceReporting__TimeoutSeconds=10
+```
+
+`PrometheusBaseUrl` 必须指向可访问 `/api/v1/query` 和 `/api/v1/query_range` 的
+Prometheus 兼容接口，令牌应仅具有查询权限。未启用、未配置或指标源暂时不可用时，页面
+会显示明确的空状态，不会改查业务数据库或拖慢正常请求。若 Collector/Prometheus 对
+指标名或 `service_name` 标签做了转换，可通过 `PerformanceReporting` 下对应的
+`*MetricName` 和 `ServiceNameLabel` 配置项适配，无需改前端。
+
+### 后台任务与 RabbitMQ
+
+自动排课、课表发布和补考自动生成使用数据库 Outbox 保存任务消息。创建业务任务与
+Outbox 消息在同一次 MySQL 提交中完成，后台发布器再将消息投递给任务 Worker；重复
+投递通过 Outbox 处理租约和唯一任务键抑制。任务状态表仍是前端查询进度与错误信息的
+唯一来源。
+
+开发和单机部署默认使用有界进程内队列，不需要 RabbitMQ：
+
+```text
+BackgroundJobs__Transport=InMemory
+```
+
+多实例生产部署应切换为 RabbitMQ，并配置独立账号、虚拟主机和 TLS：
+
+```text
+BackgroundJobs__Transport=RabbitMq
+BackgroundJobs__AutomaticScheduleConcurrency=1
+BackgroundJobs__SchedulePublishConcurrency=1
+BackgroundJobs__MakeupExamAutoConcurrency=1
+BackgroundJobs__ExamArrangementConcurrency=1
+RabbitMq__HostName=rabbitmq.example.edu.cn
+RabbitMq__Port=5671
+RabbitMq__UserName=jiaowu
+RabbitMq__Password=REPLACE_WITH_A_STRONG_PASSWORD
+RabbitMq__VirtualHost=/jiaowu
+RabbitMq__UseTls=true
+RabbitMq__TlsServerName=rabbitmq.example.edu.cn
+```
+
+RabbitMQ 传输使用持久消息、发布确认、手动消费确认、每种任务独立队列和死信队列。
+默认创建 Quorum Queue，重任务的消费者预取数为 1。三类任务各自至少有一个消费者，
+因此不同类型的任务不会再互相阻塞；单类任务的并发度可独立设置为 1-16。自动排课
+通常最消耗 CPU，建议先保持为 1，再根据 CPU、数据库连接池和任务等待时间逐级调到
+2 或 3；不要只提高预取数。
+
+Outbox 租约恢复改为按维护周期执行，避免积压发布时每条消息都额外扫描数据库；已完成
+消息默认保留 14 天并按每批 500 条清理，可使用 `CompletedRetentionDays`、
+`MaintenanceIntervalSeconds` 和 `CleanupBatchSize` 调整。应用暴露
+`Jiaowu.BackgroundJobs` Meter，其中包含发布量、处理量、发布耗时、处理耗时和清理量，
+可接入现有 OpenTelemetry/运行时指标采集器。MySQL 或 RabbitMQ 暂时不可用时，未完成
+消息会根据 Outbox 状态和租约继续补投。迁移服务应先应用
+`BackgroundJobOutbox` 数据库迁移，再启动应用实例。
+
+### 运维与审计控制台
+
+超级管理员可从“组织与权限 → 运维与审计”查看系统性能，查询写操作日志、三类失败后台
+任务、数据库、缓存与任务通道健康状态，并查看由 5xx、失败/重试任务、健康探针和备份
+时效汇总出的异常告警。查询接口和备份操作均在后端强制要求 `SuperAdmin`，不能只依赖
+前端菜单隐藏。
+
+SQLite 开发环境直接使用在线备份 API。MySQL 环境需要在服务器安装 `mysqldump` 与
+`mysql`（容器镜像已包含对应的 `mariadb-dump` 与 `mariadb` 客户端），并配置独立的
+`ConnectionStrings__OperationsMySql`。该账号不得复用日常业务账号：它需要读取业务库，
+并只应被授权创建和删除名称为 `jiaowu_restore_drill_*` 的临时演练库。恢复演练不会覆盖
+当前业务库，流程是“校验 SHA-256 → 恢复到随机临时库 → 检查表结构 → 删除临时库”。
+
+备份目录必须是仅服务账号可写的持久化目录。示例配置使用
+`/var/lib/jiaowu/backups`；Compose 已挂载独立命名卷。启用 MySQL TLS 时，还要通过
+`Operations__MySqlAdditionalArguments__N` 传入与所选命令行客户端匹配的 CA 与主机名
+校验参数。例如 Oracle MySQL 客户端使用 `--ssl-mode=VERIFY_IDENTITY` 和
+`--ssl-ca=/etc/jiaowu/mysql-ca.pem`，容器内 MariaDB 客户端使用 `--ssl`、
+`--ssl-ca=...` 与 `--ssl-verify-server-cert`。
 
 ## 跨平台发布与 Docker
 

compose.app.example.yml

@@ -17,11 +17,15 @@ services:
       options:
         max-size: "10m"
         max-file: "3"
+    volumes:
+      - jiaowu-backups:/var/lib/jiaowu/backups
 
     # 如果 .env 中的 SslCa=/etc/jiaowu/mysql-ca.pem，请把 CA 放到
-    # ./certs/mysql-ca.pem，并取消下面三行注释。
+    # ./certs/mysql-ca.pem，并在上面的 volumes 中追加以下四行。
-    # volumes:
     #   - type: bind
     #     source: ./certs/mysql-ca.pem
     #     target: /etc/jiaowu/mysql-ca.pem
     #     read_only: true
+
+volumes:
+  jiaowu-backups:

compose.example.yml

@@ -13,12 +13,27 @@ x-jiaowu-environment: &jiaowu-environment
   Database__ApplyMigrationsOnStartup: "false"
   Database__CommandTimeoutSeconds: "30"
   ConnectionStrings__MySql: "Server=mysql;Port=3306;Database=${MYSQL_DATABASE:-jiaowu_demo};User=${MYSQL_USER:-jiaowu};Password=${MYSQL_PASSWORD:?请在 .env.docker 中设置 MYSQL_PASSWORD};SslMode=Disabled;"
+  ConnectionStrings__Redis: "redis:6379,abortConnect=false"
+  Cache__Enabled: "true"
+  Cache__KeyPrefix: "jiaowu:v1"
+  BackgroundJobs__Transport: RabbitMq
+  BackgroundJobs__AutomaticScheduleConcurrency: "${BACKGROUND_JOB_AUTOMATIC_SCHEDULE_CONCURRENCY:-1}"
+  BackgroundJobs__SchedulePublishConcurrency: "${BACKGROUND_JOB_SCHEDULE_PUBLISH_CONCURRENCY:-1}"
+  BackgroundJobs__MakeupExamAutoConcurrency: "${BACKGROUND_JOB_MAKEUP_EXAM_AUTO_CONCURRENCY:-1}"
+  BackgroundJobs__ExamArrangementConcurrency: "${BACKGROUND_JOB_EXAM_ARRANGEMENT_CONCURRENCY:-1}"
+  RabbitMq__HostName: rabbitmq
+  RabbitMq__Port: "5672"
+  RabbitMq__UserName: "${RABBITMQ_USER:-jiaowu}"
+  RabbitMq__Password: "${RABBITMQ_PASSWORD:?请在 .env.docker 中设置 RABBITMQ_PASSWORD}"
+  RabbitMq__VirtualHost: "/"
+  RabbitMq__UseTls: "false"
   Jwt__Issuer: Jiaowu.Api
   Jwt__Audience: Jiaowu.Web
   Jwt__Key: "${JWT_KEY:?请在 .env.docker 中设置 JWT_KEY}"
   Jwt__ExpireMinutes: "60"
   AllowedHosts: "${ALLOWED_HOSTS:-localhost}"
   Cors__Origins__0: "${CORS_ORIGIN:-http://localhost:8080}"
+  OfficialDocuments__PublicBaseUrl: "${OFFICIAL_DOCUMENTS_PUBLIC_BASE_URL:-http://localhost:8080}"
   SeedAdmin__UserName: "${SEED_ADMIN_USERNAME:-}"
   SeedAdmin__Password: "${SEED_ADMIN_PASSWORD:-}"
   SeedAdmin__DisplayName: "${SEED_ADMIN_DISPLAY_NAME:-}"
@@ -30,6 +45,49 @@ x-json-logging: &json-logging
     max-file: "3"
 
 services:
+  rabbitmq:
+    image: rabbitmq:4.2-management-alpine
+    restart: unless-stopped
+    environment:
+      RABBITMQ_DEFAULT_USER: "${RABBITMQ_USER:-jiaowu}"
+      RABBITMQ_DEFAULT_PASS: "${RABBITMQ_PASSWORD:?请在 .env.docker 中设置 RABBITMQ_PASSWORD}"
+    healthcheck:
+      test:
+        - CMD
+        - rabbitmq-diagnostics
+        - -q
+        - ping
+      interval: 10s
+      timeout: 5s
+      retries: 12
+      start_period: 20s
+    volumes:
+      - rabbitmq-data:/var/lib/rabbitmq
+    logging: *json-logging
+
+  redis:
+    image: redis:8.8-alpine
+    restart: unless-stopped
+    command:
+      - redis-server
+      - --save
+      - ""
+      - --appendonly
+      - "no"
+      - --maxmemory
+      - 256mb
+      - --maxmemory-policy
+      - allkeys-lfu
+    healthcheck:
+      test:
+        - CMD
+        - redis-cli
+        - ping
+      interval: 5s
+      timeout: 3s
+      retries: 10
+    logging: *json-logging
+
   mysql:
     image: mysql:8.4
     restart: unless-stopped
@@ -69,6 +127,10 @@ services:
     <<: *jiaowu-image
     environment: *jiaowu-environment
     depends_on:
+      rabbitmq:
+        condition: service_healthy
+      redis:
+        condition: service_started
       mysql:
         condition: service_healthy
       migrate:
@@ -77,6 +139,8 @@ services:
       - "${JIAOWU_PORT:-8080}:8080"
     restart: unless-stopped
     init: true
+    volumes:
+      - backup-data:/var/lib/jiaowu/backups
     logging: *json-logging
 
   # 工具型一次性服务：普通 docker compose up 不会执行它。
@@ -99,3 +163,5 @@ services:
 
 volumes:
   mysql-data:
+  rabbitmq-data:
+  backup-data:

src/Jiaowu.Api/Controllers/AcademicPlanningController.cs

@@ -0,0 +1,621 @@
+using System.ComponentModel.DataAnnotations;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Graduation;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Controllers;
+
+[ApiController]
+[Authorize(Roles = SystemRoles.Student)]
+[Route("api/student/academic-planning")]
+public sealed class AcademicPlanningController(
+    AppDbContext db,
+    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+{
+    [HttpGet]
+    public async Task<ActionResult> Get(CancellationToken cancellationToken)
+    {
+        var loaded = await LoadAsync(cancellationToken);
+        if (loaded.Error is not null) return loaded.Error;
+        var context = loaded.Context!;
+
+        var completion = CurriculumCompletionRules.Evaluate(
+            context.Plan.Modules,
+            context.PassedCourseIds);
+        var planCompletedCredits = context.Courses
+            .Where(x => context.PassedCourseIds.Contains(x.CourseId))
+            .Sum(x => x.Credits);
+        var suggestionIds = AcademicPlanningRules.SuggestNextSemester(
+            context.CourseSnapshots,
+            context.PassedCourseIds,
+            context.InProgressCourseIds,
+            context.NextSemester);
+        var suggestionIdSet = suggestionIds.ToHashSet();
+        var latestAudit = await db.GraduationAuditResults.AsNoTracking()
+            .Where(x =>
+                x.StudentId == context.Student.Id &&
+                x.GraduationAuditBatch!.Status ==
+                    GraduationAuditBatchStatus.Published)
+            .OrderByDescending(x => x.GraduationAuditBatch!.GraduationYear)
+            .ThenByDescending(x => x.GraduationAuditBatch!.PublishedAt)
+            .Select(x => new
+            {
+                BatchName = x.GraduationAuditBatch!.Name,
+                x.GraduationAuditBatch.GraduationYear,
+                x.RequiredCredits,
+                x.EarnedCredits,
+                x.RequiredCourseCount,
+                x.PassedRequiredCourseCount,
+                x.FailedCourseCount,
+                x.MissingCourseNames,
+                x.Conclusion,
+                x.IsOverridden,
+                x.ReviewComment,
+                x.GraduationAuditBatch.PublishedAt
+            })
+            .FirstOrDefaultAsync(cancellationToken);
+
+        var endSemester = Math.Max(
+            context.Plan.Major!.SchoolingYears * 2,
+            context.NextSemester + 3);
+        return Ok(new
+        {
+            Student = new
+            {
+                context.Student.Id,
+                context.Student.StudentNumber,
+                context.Student.Name,
+                context.Student.EnrollmentYear,
+                context.Student.Status,
+                ClassName = context.Student.AdministrativeClass!.Name,
+                MajorName = context.Student.AdministrativeClass.Major!.Name,
+                CollegeName =
+                    context.Student.AdministrativeClass.Major.College!.Name
+            },
+            Plan = new
+            {
+                context.Plan.Id,
+                context.Plan.Name,
+                context.Plan.Version,
+                context.Plan.TotalCredits,
+                SchoolingYears = context.Plan.Major.SchoolingYears,
+                CurrentSemester = context.CurrentSemester,
+                NextSemester = context.NextSemester,
+                StandardGraduationSemester =
+                    context.Plan.Major.SchoolingYears * 2
+            },
+            Baseline = new
+            {
+                EarnedCredits = context.EarnedCredits,
+                PlanCompletedCredits = planCompletedCredits,
+                CreditGap = Math.Max(
+                    context.Plan.TotalCredits - context.EarnedCredits,
+                    0),
+                CompletionRate = context.Plan.TotalCredits <= 0
+                    ? 0
+                    : Math.Min(100, Math.Round(
+                        planCompletedCredits / context.Plan.TotalCredits * 100,
+                        1)),
+                completion.RequirementCount,
+                completion.PassedRequirementCount,
+                completion.MissingRequirements,
+                InProgressCredits = context.Courses
+                    .Where(x => context.InProgressCourseIds.Contains(x.CourseId))
+                    .Sum(x => x.Credits)
+            },
+            Terms = Enumerable.Range(
+                    context.NextSemester,
+                    endSemester - context.NextSemester + 1)
+                .Select(semester => new
+                {
+                    Semester = semester,
+                    Label = FormatSemester(
+                        context.Student.EnrollmentYear,
+                        semester),
+                    IsBeyondStandard =
+                        semester > context.Plan.Major.SchoolingYears * 2
+                }),
+            Courses = context.Courses
+                .OrderBy(x => x.RecommendedSemester)
+                .ThenBy(x => x.CourseCode)
+                .Select(course => new
+                {
+                    course.CourseId,
+                    course.CourseCode,
+                    course.CourseName,
+                    course.Credits,
+                    course.RecommendedSemester,
+                    course.Type,
+                    course.ModuleCode,
+                    course.ModuleName,
+                    Status = context.StatusByCourse[course.CourseId],
+                    IsSuggested = suggestionIdSet.Contains(course.CourseId),
+                    Prerequisites = course.Prerequisites.Select(item => new
+                    {
+                        item.CourseId,
+                        item.CourseCode,
+                        item.CourseName,
+                        IsCompleted =
+                            context.PassedCourseIds.Contains(item.CourseId),
+                        IsInProgress =
+                            context.InProgressCourseIds.Contains(item.CourseId)
+                    })
+                }),
+            NextSemesterSuggestion = suggestionIds.Select(courseId =>
+            {
+                var course = context.CourseById[courseId];
+                return new
+                {
+                    course.CourseId,
+                    course.CourseCode,
+                    course.CourseName,
+                    course.Credits,
+                    course.Type,
+                    Reason = course.Type == CurriculumCourseType.Required &&
+                             course.RecommendedSemester <= context.NextSemester
+                        ? "计划学期已到，且先修条件已满足"
+                        : course.Type == CurriculumCourseType.Required
+                            ? "必修课程，按培养方案顺序推进"
+                            : "用于补足培养模块与总学分"
+                };
+            }),
+            LatestGraduationAudit = latestAudit,
+            Assumptions = new[]
+            {
+                "模拟课程按顺利通过计算，不会写入成绩或正式选课。",
+                $"预计毕业学期按每学期最多 {AcademicPlanningRules.RecommendedSemesterCreditLimit:0} 学分估算。",
+                "当前在读课程按本学期顺利完成计入预测。"
+            }
+        });
+    }
+
+    [HttpPost("simulate")]
+    public async Task<ActionResult> Simulate(
+        AcademicPlanningRequest request,
+        CancellationToken cancellationToken)
+    {
+        var loaded = await LoadAsync(cancellationToken);
+        if (loaded.Error is not null) return loaded.Error;
+        var context = loaded.Context!;
+
+        var selections = request.Terms
+            .SelectMany(term => term.CourseIds.Select(courseId => new
+            {
+                term.Semester,
+                CourseId = courseId
+            }))
+            .ToList();
+        var duplicate = selections
+            .GroupBy(x => x.CourseId)
+            .FirstOrDefault(group => group.Count() > 1);
+        if (duplicate is not null)
+            return ValidationProblem("同一门课程不能安排在多个学期。");
+        if (request.Terms.Any(x =>
+                x.Semester < context.NextSemester ||
+                x.Semester > context.NextSemester + 12))
+            return ValidationProblem("模拟学期超出了可规划范围。");
+
+        var invalidCourse = selections.FirstOrDefault(x =>
+            !context.CourseById.ContainsKey(x.CourseId));
+        if (invalidCourse is not null)
+            return ValidationProblem("模拟计划包含不属于当前培养方案的课程。");
+        var alreadyHandled = selections.FirstOrDefault(x =>
+            context.PassedCourseIds.Contains(x.CourseId) ||
+            context.InProgressCourseIds.Contains(x.CourseId));
+        if (alreadyHandled is not null)
+            return ValidationProblem("已完成或当前在读课程无需重复安排。");
+
+        var plannedSemesters = selections.ToDictionary(
+            x => x.CourseId,
+            x => x.Semester);
+        var projectedCourseIds = context.PassedCourseIds
+            .Concat(context.InProgressCourseIds)
+            .Concat(plannedSemesters.Keys)
+            .ToHashSet();
+        var completion = CurriculumCompletionRules.Evaluate(
+            context.Plan.Modules,
+            projectedCourseIds);
+        var addedCredits = context.Courses
+            .Where(x =>
+                !context.PassedCourseIds.Contains(x.CourseId) &&
+                (context.InProgressCourseIds.Contains(x.CourseId) ||
+                 plannedSemesters.ContainsKey(x.CourseId)))
+            .Sum(x => x.Credits);
+        var projectedEarnedCredits = context.EarnedCredits + addedCredits;
+        var creditGap = Math.Max(
+            context.Plan.TotalCredits - projectedEarnedCredits,
+            0);
+        var prerequisiteIssues = AcademicPlanningRules.FindPrerequisiteIssues(
+            context.CourseSnapshots,
+            context.PassedCourseIds,
+            context.InProgressCourseIds,
+            plannedSemesters);
+        var conflicts = prerequisiteIssues.Select(issue =>
+        {
+            var course = context.CourseById[issue.CourseId];
+            var prerequisite = context.AllCourseLabels.GetValueOrDefault(
+                issue.PrerequisiteCourseId,
+                new CourseLabel(
+                    issue.PrerequisiteCourseId,
+                    "未知课程",
+                    "未找到的先修课程"));
+            return new
+            {
+                Type = "Prerequisite",
+                issue.CourseId,
+                course.CourseName,
+                PrerequisiteCourseId = prerequisite.CourseId,
+                PrerequisiteCourseName = prerequisite.CourseName,
+                issue.PlannedSemester,
+                issue.PrerequisitePlannedSemester,
+                Message = issue.PrerequisitePlannedSemester.HasValue
+                    ? $"《{prerequisite.CourseName}》必须安排在《{course.CourseName}》之前。"
+                    : $"《{course.CourseName}》的先修课程《{prerequisite.CourseName}》尚未完成或安排。"
+            };
+        }).ToList();
+        var workloadWarnings = request.Terms
+            .Select(term => new
+            {
+                term.Semester,
+                Credits = term.CourseIds.Sum(courseId =>
+                    context.CourseById.GetValueOrDefault(courseId)?.Credits ?? 0)
+            })
+            .Where(x =>
+                x.Credits > AcademicPlanningRules.HeavySemesterCreditLimit)
+            .Select(x => new
+            {
+                Type = "Workload",
+                x.Semester,
+                x.Credits,
+                Message =
+                    $"第 {x.Semester} 学期安排了 {x.Credits:0.#} 学分，超过建议上限 {AcademicPlanningRules.HeavySemesterCreditLimit:0.#} 学分。"
+            })
+            .ToList();
+        var timingWarnings = selections
+            .Select(item => new
+            {
+                item.Semester,
+                Course = context.CourseById[item.CourseId]
+            })
+            .Where(x => x.Semester < x.Course.RecommendedSemester)
+            .Select(x => new
+            {
+                Type = "EarlyCourse",
+                x.Course.CourseId,
+                x.Course.CourseName,
+                x.Semester,
+                x.Course.RecommendedSemester,
+                Message =
+                    $"《{x.Course.CourseName}》早于培养方案建议学期修读，请确认课程开设条件。"
+            })
+            .ToList();
+
+        var unresolvedFailedCourseCount = context.FailedCourseIds.Count(
+            courseId => !projectedCourseIds.Contains(courseId));
+        var conclusion = GraduationAuditRules.Evaluate(
+            true,
+            context.Student.Status,
+            context.Plan.TotalCredits,
+            projectedEarnedCredits,
+            completion.RequirementCount,
+            completion.PassedRequirementCount,
+            unresolvedFailedCourseCount);
+        var latestPlannedSemester = plannedSemesters.Count == 0
+            ? context.NextSemester - 1
+            : plannedSemesters.Values.Max();
+        var estimatedSemester =
+            AcademicPlanningRules.EstimateCompletionSemester(
+                context.NextSemester,
+                latestPlannedSemester,
+                creditGap,
+                completion.RequirementCount -
+                completion.PassedRequirementCount);
+        var remainingRequiredSemesterFloor = context.Courses
+            .Where(course =>
+                course.Type == CurriculumCourseType.Required &&
+                !projectedCourseIds.Contains(course.CourseId))
+            .Select(course => course.RecommendedSemester)
+            .DefaultIfEmpty(estimatedSemester)
+            .Max();
+        estimatedSemester = Math.Max(
+            estimatedSemester,
+            remainingRequiredSemesterFloor);
+        var planCompletedCredits = context.Courses
+            .Where(x => projectedCourseIds.Contains(x.CourseId))
+            .Sum(x => x.Credits);
+
+        return Ok(new
+        {
+            Projected = new
+            {
+                EarnedCredits = projectedEarnedCredits,
+                PlanCompletedCredits = planCompletedCredits,
+                CreditGap = creditGap,
+                CompletionRate = context.Plan.TotalCredits <= 0
+                    ? 0
+                    : Math.Min(100, Math.Round(
+                        planCompletedCredits / context.Plan.TotalCredits * 100,
+                        1)),
+                completion.RequirementCount,
+                completion.PassedRequirementCount,
+                completion.MissingRequirements,
+                UnresolvedFailedCourseCount = unresolvedFailedCourseCount,
+                GraduationConclusion = conclusion,
+                EstimatedGraduationSemester = estimatedSemester,
+                EstimatedGraduationTerm = FormatSemester(
+                    context.Student.EnrollmentYear,
+                    estimatedSemester),
+                IsBeyondStandard =
+                    estimatedSemester >
+                    context.Plan.Major!.SchoolingYears * 2
+            },
+            Conflicts = conflicts,
+            Warnings = workloadWarnings.Cast<object>()
+                .Concat(timingWarnings)
+                .ToList(),
+            TermSummaries = request.Terms
+                .OrderBy(x => x.Semester)
+                .Select(term => new
+                {
+                    term.Semester,
+                    Label = FormatSemester(
+                        context.Student.EnrollmentYear,
+                        term.Semester),
+                    CourseCount = term.CourseIds.Count,
+                    Credits = term.CourseIds.Sum(courseId =>
+                        context.CourseById.GetValueOrDefault(courseId)?.Credits ??
+                        0)
+                })
+        });
+    }
+
+    private async Task<LoadResult> LoadAsync(CancellationToken cancellationToken)
+    {
+        var userId = currentUserDataScope.Current.UserId;
+        var student = await db.Students.AsNoTracking()
+            .Include(x => x.AdministrativeClass)
+            .ThenInclude(x => x!.Major)
+            .ThenInclude(x => x!.College)
+            .FirstOrDefaultAsync(x => x.UserId == userId, cancellationToken);
+        if (student is null)
+            return new LoadResult(
+                null,
+                ConflictProblem("当前账号尚未关联学生档案。"));
+
+        var plan = await db.CurriculumPlans.AsNoTracking()
+            .AsSplitQuery()
+            .Include(x => x.Major)
+            .Include(x => x.Modules)
+            .ThenInclude(x => x.Courses)
+            .ThenInclude(x => x.Course)
+            .ThenInclude(x => x!.Prerequisites)
+            .ThenInclude(x => x.PrerequisiteCourse)
+            .Where(x =>
+                x.MajorId == student.AdministrativeClass!.MajorId &&
+                x.EffectiveGrade == student.EnrollmentYear &&
+                x.Status == CurriculumPlanStatus.Published)
+            .OrderByDescending(x => x.PublishedAt)
+            .FirstOrDefaultAsync(cancellationToken);
+        if (plan is null)
+            return new LoadResult(
+                null,
+                ConflictProblem(
+                    $"{student.EnrollmentYear} 级{student.AdministrativeClass!.Major!.Name}尚未发布培养方案。"));
+
+        var courses = plan.Modules
+            .SelectMany(module => module.Courses.Select(item =>
+                new PlanningCourse(
+                    item.CourseId,
+                    item.Course!.Code,
+                    item.Course.Name,
+                    item.Course.Credits,
+                    item.RecommendedSemester,
+                    item.Type,
+                    module.Code,
+                    module.Name,
+                    item.Course.Prerequisites
+                        .Select(prerequisite => new CourseLabel(
+                            prerequisite.PrerequisiteCourseId,
+                            prerequisite.PrerequisiteCourse!.Code,
+                            prerequisite.PrerequisiteCourse.Name))
+                        .OrderBy(x => x.CourseCode)
+                        .ToList())))
+            .GroupBy(x => x.CourseId)
+            .Select(group => group.First())
+            .ToList();
+        var planCourseIds = courses.Select(x => x.CourseId).ToArray();
+
+        var gradeAttempts = await db.GradeRecords.AsNoTracking()
+            .Where(x =>
+                x.StudentId == student.Id &&
+                x.GradeSheet!.Status == GradeSheetStatus.Published)
+            .Select(x => new GradeAttempt(
+                x.GradeSheet!.TeachingTask!.CourseId,
+                x.GradeSheet.TeachingTask.Course!.Credits,
+                x.TotalScore,
+                x.ExamStatus))
+            .ToListAsync(cancellationToken);
+        var passedCourseIds = gradeAttempts
+            .Where(x => StudentCourseProgressRules.IsPassed(
+                new StudentCourseAttemptSnapshot(x.TotalScore, x.ExamStatus)))
+            .Select(x => x.CourseId)
+            .Distinct()
+            .ToHashSet();
+        var failedCourseIds = gradeAttempts
+            .GroupBy(x => x.CourseId)
+            .Where(group => !group.Any(x =>
+                StudentCourseProgressRules.IsPassed(
+                    new StudentCourseAttemptSnapshot(
+                        x.TotalScore,
+                        x.ExamStatus))))
+            .Select(group => group.Key)
+            .ToHashSet();
+        var earnedCredits = gradeAttempts
+            .Where(x => passedCourseIds.Contains(x.CourseId))
+            .GroupBy(x => x.CourseId)
+            .Sum(group => group.Max(x => x.Credits));
+
+        var inProgressCourseIds = await db.TeachingTasks.AsNoTracking()
+            .Where(task =>
+                task.Status == TeachingTaskStatus.Published &&
+                task.AcademicTerm!.IsCurrent &&
+                (task.Classes.Any(item =>
+                     item.AdministrativeClassId ==
+                     student.AdministrativeClassId) ||
+                 db.CourseEnrollments.Any(enrollment =>
+                     enrollment.StudentId == student.Id &&
+                     enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                     enrollment.CourseSelectionOffering!.TeachingTaskId ==
+                     task.Id)))
+            .Select(x => x.CourseId)
+            .Distinct()
+            .ToListAsync(cancellationToken);
+        var inProgressSet = inProgressCourseIds
+            .Where(planCourseIds.Contains)
+            .Where(courseId => !passedCourseIds.Contains(courseId))
+            .ToHashSet();
+
+        var attemptsByCourse = gradeAttempts
+            .Where(x => planCourseIds.Contains(x.CourseId))
+            .GroupBy(x => x.CourseId)
+            .ToDictionary(x => x.Key, x => x.ToList());
+        var statuses = courses.ToDictionary(
+            x => x.CourseId,
+            x => StudentCourseProgressRules.Evaluate(
+                attemptsByCourse.GetValueOrDefault(x.CourseId, [])
+                    .Select(attempt => new StudentCourseAttemptSnapshot(
+                        attempt.TotalScore,
+                        attempt.ExamStatus)),
+                inProgressSet.Contains(x.CourseId)).Status);
+        var currentTerm = await db.AcademicTerms.AsNoTracking()
+            .Where(x => x.IsCurrent)
+            .OrderByDescending(x => x.StartDate)
+            .FirstOrDefaultAsync(cancellationToken);
+        var currentSemester = CalculateCurrentSemester(
+            student.EnrollmentYear,
+            currentTerm);
+        var snapshots = courses.Select(x =>
+            new AcademicPlanningCourseSnapshot(
+                x.CourseId,
+                x.CourseName,
+                x.Credits,
+                x.RecommendedSemester,
+                x.Type,
+                x.Prerequisites.Select(p => p.CourseId).ToArray()))
+            .ToList();
+        var allLabels = courses
+            .Select(x => new CourseLabel(
+                x.CourseId,
+                x.CourseCode,
+                x.CourseName))
+            .Concat(courses.SelectMany(x => x.Prerequisites))
+            .GroupBy(x => x.CourseId)
+            .ToDictionary(x => x.Key, x => x.First());
+
+        return new LoadResult(
+            new PlanningContext(
+                student,
+                plan,
+                courses,
+                courses.ToDictionary(x => x.CourseId),
+                snapshots,
+                allLabels,
+                passedCourseIds,
+                inProgressSet,
+                failedCourseIds,
+                statuses,
+                earnedCredits,
+                currentSemester,
+                currentSemester + 1),
+            null);
+    }
+
+    private static int CalculateCurrentSemester(
+        int enrollmentYear,
+        AcademicTerm? currentTerm)
+    {
+        if (currentTerm is not null)
+        {
+            return Math.Max(
+                1,
+                currentTerm.Season == TermSeason.Autumn
+                    ? (currentTerm.StartDate.Year - enrollmentYear) * 2 + 1
+                    : (currentTerm.StartDate.Year - enrollmentYear - 1) * 2 + 2);
+        }
+
+        var today = DateOnly.FromDateTime(DateTime.Today);
+        return Math.Max(
+            1,
+            today.Month >= 8
+                ? (today.Year - enrollmentYear) * 2 + 1
+                : (today.Year - enrollmentYear - 1) * 2 + 2);
+    }
+
+    private static string FormatSemester(int enrollmentYear, int semester)
+    {
+        var startYear = enrollmentYear + (semester - 1) / 2;
+        var season = semester % 2 == 1 ? "秋季学期" : "春季学期";
+        return $"{startYear}—{startYear + 1} 学年{season}";
+    }
+
+    private ActionResult ConflictProblem(string detail) =>
+        Conflict(new ProblemDetails
+        {
+            Title = "无法进行学业规划",
+            Detail = detail,
+            Status = StatusCodes.Status409Conflict
+        });
+
+    private sealed record GradeAttempt(
+        Guid CourseId,
+        decimal Credits,
+        decimal? TotalScore,
+        GradeExamStatus ExamStatus);
+
+    private sealed record CourseLabel(
+        Guid CourseId,
+        string CourseCode,
+        string CourseName);
+
+    private sealed record PlanningCourse(
+        Guid CourseId,
+        string CourseCode,
+        string CourseName,
+        decimal Credits,
+        int RecommendedSemester,
+        CurriculumCourseType Type,
+        string ModuleCode,
+        string ModuleName,
+        IReadOnlyList<CourseLabel> Prerequisites);
+
+    private sealed record PlanningContext(
+        Student Student,
+        CurriculumPlan Plan,
+        IReadOnlyList<PlanningCourse> Courses,
+        IReadOnlyDictionary<Guid, PlanningCourse> CourseById,
+        IReadOnlyList<AcademicPlanningCourseSnapshot> CourseSnapshots,
+        IReadOnlyDictionary<Guid, CourseLabel> AllCourseLabels,
+        IReadOnlySet<Guid> PassedCourseIds,
+        IReadOnlySet<Guid> InProgressCourseIds,
+        IReadOnlySet<Guid> FailedCourseIds,
+        IReadOnlyDictionary<Guid, StudentCourseProgressStatus> StatusByCourse,
+        decimal EarnedCredits,
+        int CurrentSemester,
+        int NextSemester);
+
+    private sealed record LoadResult(
+        PlanningContext? Context,
+        ActionResult? Error);
+}
+
+public sealed record AcademicPlanningRequest(
+    IReadOnlyCollection<AcademicPlanningTermRequest> Terms);
+
+public sealed record AcademicPlanningTermRequest(
+    [Range(1, 30)] int Semester,
+    IReadOnlyCollection<Guid> CourseIds);

src/Jiaowu.Api/Controllers/AppUpdatesController.cs

@@ -0,0 +1,440 @@
+using System.ComponentModel.DataAnnotations;
+using System.Data;
+using System.IO.Compression;
+using System.Security.Cryptography;
+using System.Text.RegularExpressions;
+using Jiaowu.Api.Contracts;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Domain.System;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.RateLimiting;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Controllers;
+
+[ApiController]
+[Route("api/app-updates")]
+public sealed partial class AppUpdatesController(AppDbContext db) : ControllerBase
+{
+    private const long MaximumBundleBytes = 30 * 1024 * 1024;
+    private const long MaximumExpandedBytes = 150 * 1024 * 1024;
+    private const int MaximumZipEntries = 10_000;
+
+    [AllowAnonymous]
+    [EnableRateLimiting("app-updates")]
+    [HttpGet("latest")]
+    public async Task<ActionResult<AppUpdateCheckResponse>> GetLatest(
+        [FromQuery, Required] string platform,
+        [FromQuery, Required] string nativeVersion,
+        [FromQuery] string channel = "production",
+        [FromQuery] string? currentVersion = null,
+        CancellationToken cancellationToken = default)
+    {
+        if (!TryParsePlatform(platform, out var parsedPlatform))
+            return ValidationProblem("平台必须为 android 或 ios。");
+        if (!TryParseChannel(channel, out var parsedChannel))
+            return ValidationProblem("更新通道必须为 production 或 staging。");
+
+        var normalizedNativeVersion = nativeVersion.Trim();
+        if (!NativeVersionRegex().IsMatch(normalizedNativeVersion))
+            return ValidationProblem("原生版本格式无效。");
+
+        var release = await db.AppUpdateReleases.AsNoTracking()
+            .Where(x =>
+                x.Platform == parsedPlatform &&
+                x.Channel == parsedChannel &&
+                x.NativeVersion == normalizedNativeVersion &&
+                x.Status == AppUpdateReleaseStatus.Published)
+            .OrderByDescending(x => x.PublishedAt)
+            .FirstOrDefaultAsync(cancellationToken);
+
+        if (release is null ||
+            string.Equals(
+                release.Version,
+                currentVersion?.Trim(),
+                StringComparison.OrdinalIgnoreCase))
+        {
+            return Ok(new AppUpdateCheckResponse(
+                false,
+                release?.Version,
+                normalizedNativeVersion,
+                parsedPlatform,
+                parsedChannel,
+                null,
+                release?.ReleaseNotes,
+                release?.FileSize,
+                release?.Sha256,
+                release?.PublishedAt));
+        }
+
+        return Ok(new AppUpdateCheckResponse(
+            true,
+            release.Version,
+            release.NativeVersion,
+            release.Platform,
+            release.Channel,
+            $"app-updates/releases/{release.Id}/bundle",
+            release.ReleaseNotes,
+            release.FileSize,
+            release.Sha256,
+            release.PublishedAt));
+    }
+
+    [AllowAnonymous]
+    [EnableRateLimiting("app-updates")]
+    [HttpGet("releases/{id:guid}/bundle")]
+    public async Task<IActionResult> DownloadBundle(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var release = await db.AppUpdateReleases.AsNoTracking()
+            .Where(x =>
+                x.Id == id &&
+                x.Status != AppUpdateReleaseStatus.Draft)
+            .Select(x => new
+            {
+                x.BundleContent,
+                x.FileName,
+                x.Sha256
+            })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (release is null) return NotFound();
+
+        Response.Headers.ETag = $"\"sha256-{release.Sha256}\"";
+        Response.Headers.CacheControl = "public,max-age=31536000,immutable";
+        return File(
+            release.BundleContent,
+            "application/zip",
+            release.FileName,
+            enableRangeProcessing: true);
+    }
+
+    [Authorize(Roles = SystemRoles.SuperAdmin)]
+    [HttpGet("releases")]
+    public async Task<ActionResult<PagedResult<AppUpdateReleaseItem>>> GetReleases(
+        [FromQuery] int page = 1,
+        [FromQuery] int pageSize = 20,
+        [FromQuery] string? platform = null,
+        [FromQuery] string? channel = null,
+        CancellationToken cancellationToken = default)
+    {
+        if (page < 1 || pageSize is < 1 or > 100)
+            return ValidationProblem("页码必须大于零，每页数量必须在 1 到 100 之间。");
+
+        var query = db.AppUpdateReleases.AsNoTracking().AsQueryable();
+        if (!string.IsNullOrWhiteSpace(platform))
+        {
+            if (!TryParsePlatform(platform, out var parsedPlatform))
+                return ValidationProblem("平台必须为 android 或 ios。");
+            query = query.Where(x => x.Platform == parsedPlatform);
+        }
+        if (!string.IsNullOrWhiteSpace(channel))
+        {
+            if (!TryParseChannel(channel, out var parsedChannel))
+                return ValidationProblem("更新通道必须为 production 或 staging。");
+            query = query.Where(x => x.Channel == parsedChannel);
+        }
+
+        var total = await query.CountAsync(cancellationToken);
+        var rows = await query
+            .OrderByDescending(x => x.PublishedAt ?? x.CreatedAt)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .Select(x => new AppUpdateReleaseItem(
+                x.Id,
+                x.Platform,
+                x.Channel,
+                x.Version,
+                x.NativeVersion,
+                x.Status,
+                x.ReleaseNotes,
+                x.FileName,
+                x.FileSize,
+                x.Sha256,
+                x.CreatedByUserName,
+                x.CreatedAt,
+                x.PublishedByUserName,
+                x.PublishedAt))
+            .ToArrayAsync(cancellationToken);
+        return Ok(new PagedResult<AppUpdateReleaseItem>(
+            rows,
+            total,
+            page,
+            pageSize));
+    }
+
+    [Authorize(Roles = SystemRoles.SuperAdmin)]
+    [Consumes("multipart/form-data")]
+    [RequestSizeLimit(MaximumBundleBytes + 1024 * 1024)]
+    [HttpPost("releases")]
+    public async Task<ActionResult<AppUpdateReleaseItem>> UploadRelease(
+        [FromForm] AppUpdateUploadRequest request,
+        CancellationToken cancellationToken)
+    {
+        if (!TryParsePlatform(request.Platform, out var platform))
+            return ValidationProblem("平台必须为 android 或 ios。");
+        if (!TryParseChannel(request.Channel, out var channel))
+            return ValidationProblem("更新通道必须为 production 或 staging。");
+
+        var version = request.Version.Trim();
+        var nativeVersion = request.NativeVersion.Trim();
+        if (!ReleaseVersionRegex().IsMatch(version))
+            return ValidationProblem(
+                "热更新版本必须使用语义版本，例如 1.0.1 或 1.0.1-beta.1。");
+        if (!NativeVersionRegex().IsMatch(nativeVersion))
+            return ValidationProblem("原生版本格式无效，例如 1.0 或 1.0.0。");
+        if (request.ReleaseNotes?.Trim().Length > 1000)
+            return ValidationProblem("更新说明不能超过 1000 字。");
+        if (request.Bundle.Length is <= 0 or > MaximumBundleBytes)
+            return ValidationProblem("更新包必须大于 0 字节且不超过 30 MB。");
+
+        var exists = await db.AppUpdateReleases.AsNoTracking()
+            .AnyAsync(
+                x =>
+                    x.Platform == platform &&
+                    x.Channel == channel &&
+                    x.NativeVersion == nativeVersion &&
+                    x.Version == version,
+                cancellationToken);
+        if (exists)
+            return Conflict(new ProblemDetails
+            {
+                Title = "更新版本已存在",
+                Detail = "同一平台、通道和原生版本下不能重复上传相同版本。",
+                Status = StatusCodes.Status409Conflict
+            });
+
+        await using var source = request.Bundle.OpenReadStream();
+        await using var buffer = new MemoryStream(
+            checked((int)request.Bundle.Length));
+        await source.CopyToAsync(buffer, cancellationToken);
+        var content = buffer.ToArray();
+        var archiveError = ValidateArchive(content);
+        if (archiveError is not null) return ValidationProblem(archiveError);
+
+        var fileName = Path.GetFileName(request.Bundle.FileName.Trim());
+        if (string.IsNullOrWhiteSpace(fileName) || fileName.Length > 180)
+            fileName = $"jiaowu-web-{version}.zip";
+
+        var release = new AppUpdateRelease
+        {
+            Platform = platform,
+            Channel = channel,
+            Version = version,
+            NativeVersion = nativeVersion,
+            ReleaseNotes = NullIfWhiteSpace(request.ReleaseNotes),
+            FileName = fileName,
+            FileSize = content.LongLength,
+            Sha256 = Convert.ToHexString(
+                    SHA256.HashData(content))
+                .ToLowerInvariant(),
+            BundleContent = content,
+            CreatedByUserName = User.Identity?.Name ?? "unknown"
+        };
+        db.AppUpdateReleases.Add(release);
+        await db.SaveChangesAsync(cancellationToken);
+
+        return CreatedAtAction(
+            nameof(GetReleases),
+            new { id = release.Id },
+            ToItem(release));
+    }
+
+    [Authorize(Roles = SystemRoles.SuperAdmin)]
+    [HttpPost("releases/{id:guid}/publish")]
+    public async Task<ActionResult<AppUpdateReleaseItem>> PublishRelease(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var strategy = db.Database.CreateExecutionStrategy();
+        var published = await strategy.ExecuteAsync(async () =>
+        {
+            await using var transaction = await db.Database.BeginTransactionAsync(
+                IsolationLevel.Serializable,
+                cancellationToken);
+            var target = await db.AppUpdateReleases
+                .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+            if (target is null) return null;
+
+            var currentlyPublished = await db.AppUpdateReleases
+                .Where(x =>
+                    x.Id != target.Id &&
+                    x.Platform == target.Platform &&
+                    x.Channel == target.Channel &&
+                    x.NativeVersion == target.NativeVersion &&
+                    x.Status == AppUpdateReleaseStatus.Published)
+                .ToListAsync(cancellationToken);
+            foreach (var release in currentlyPublished)
+                release.Status = AppUpdateReleaseStatus.Archived;
+
+            target.Status = AppUpdateReleaseStatus.Published;
+            target.PublishedAt = DateTime.UtcNow;
+            target.PublishedByUserName = User.Identity?.Name ?? "unknown";
+            await db.SaveChangesAsync(cancellationToken);
+            await transaction.CommitAsync(cancellationToken);
+            return ToItem(target);
+        });
+
+        return published is null ? NotFound() : Ok(published);
+    }
+
+    [Authorize(Roles = SystemRoles.SuperAdmin)]
+    [HttpDelete("releases/{id:guid}")]
+    public async Task<IActionResult> DeleteRelease(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var release = await db.AppUpdateReleases
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (release is null) return NotFound();
+        if (release.Status == AppUpdateReleaseStatus.Published)
+            return Conflict(new ProblemDetails
+            {
+                Title = "正式版本不能删除",
+                Detail = "请先发布另一个兼容版本，再删除已归档的更新包。",
+                Status = StatusCodes.Status409Conflict
+            });
+
+        db.AppUpdateReleases.Remove(release);
+        await db.SaveChangesAsync(cancellationToken);
+        return NoContent();
+    }
+
+    private static string? ValidateArchive(byte[] content)
+    {
+        try
+        {
+            using var stream = new MemoryStream(content, writable: false);
+            using var archive = new ZipArchive(
+                stream,
+                ZipArchiveMode.Read,
+                leaveOpen: false);
+            if (archive.Entries.Count is 0 or > MaximumZipEntries)
+                return $"更新包文件数量必须在 1 到 {MaximumZipEntries} 之间。";
+
+            long expandedBytes = 0;
+            var hasRootIndex = false;
+            foreach (var entry in archive.Entries)
+            {
+                var normalized = entry.FullName.Replace('\\', '/');
+                if (normalized.StartsWith('/') ||
+                    normalized.Split('/').Any(part => part == ".."))
+                {
+                    return "更新包包含不安全的文件路径。";
+                }
+                if (string.Equals(
+                        normalized,
+                        "index.html",
+                        StringComparison.OrdinalIgnoreCase))
+                {
+                    hasRootIndex = true;
+                }
+                expandedBytes = checked(expandedBytes + entry.Length);
+                if (expandedBytes > MaximumExpandedBytes)
+                    return "更新包解压后的总大小不能超过 150 MB。";
+            }
+
+            return hasRootIndex
+                ? null
+                : "更新包根目录必须包含 index.html；请直接压缩 dist 目录中的内容。";
+        }
+        catch (Exception exception) when (
+            exception is InvalidDataException or IOException or OverflowException)
+        {
+            return "更新包不是有效的 ZIP 文件，或文件结构已损坏。";
+        }
+    }
+
+    private static bool TryParsePlatform(
+        string value,
+        out AppUpdatePlatform platform) =>
+        Enum.TryParse(value.Trim(), ignoreCase: true, out platform) &&
+        Enum.IsDefined(platform);
+
+    private static bool TryParseChannel(
+        string value,
+        out AppUpdateChannel channel) =>
+        Enum.TryParse(value.Trim(), ignoreCase: true, out channel) &&
+        Enum.IsDefined(channel);
+
+    private static string? NullIfWhiteSpace(string? value) =>
+        string.IsNullOrWhiteSpace(value) ? null : value.Trim();
+
+    private static AppUpdateReleaseItem ToItem(AppUpdateRelease release) =>
+        new(
+            release.Id,
+            release.Platform,
+            release.Channel,
+            release.Version,
+            release.NativeVersion,
+            release.Status,
+            release.ReleaseNotes,
+            release.FileName,
+            release.FileSize,
+            release.Sha256,
+            release.CreatedByUserName,
+            release.CreatedAt,
+            release.PublishedByUserName,
+            release.PublishedAt);
+
+    [GeneratedRegex(
+        @"^\d+\.\d+\.\d+(?:-[0-9A-Za-z]+(?:[.-][0-9A-Za-z]+)*)?$",
+        RegexOptions.CultureInvariant)]
+    private static partial Regex ReleaseVersionRegex();
+
+    [GeneratedRegex(
+        @"^\d+\.\d+(?:\.\d+)?(?:-[0-9A-Za-z]+(?:[.-][0-9A-Za-z]+)*)?$",
+        RegexOptions.CultureInvariant)]
+    private static partial Regex NativeVersionRegex();
+}
+
+public sealed class AppUpdateUploadRequest
+{
+    [Required]
+    public required IFormFile Bundle { get; init; }
+
+    [Required, MaxLength(20)]
+    public required string Platform { get; init; }
+
+    [Required, MaxLength(20)]
+    public required string Channel { get; init; }
+
+    [Required, MaxLength(40)]
+    public required string Version { get; init; }
+
+    [Required, MaxLength(40)]
+    public required string NativeVersion { get; init; }
+
+    [MaxLength(1000)]
+    public string? ReleaseNotes { get; init; }
+}
+
+public sealed record AppUpdateCheckResponse(
+    bool Available,
+    string? Version,
+    string NativeVersion,
+    AppUpdatePlatform Platform,
+    AppUpdateChannel Channel,
+    string? DownloadUrl,
+    string? ReleaseNotes,
+    long? FileSize,
+    string? Sha256,
+    DateTime? PublishedAt);
+
+public sealed record AppUpdateReleaseItem(
+    Guid Id,
+    AppUpdatePlatform Platform,
+    AppUpdateChannel Channel,
+    string Version,
+    string NativeVersion,
+    AppUpdateReleaseStatus Status,
+    string? ReleaseNotes,
+    string FileName,
+    long FileSize,
+    string Sha256,
+    string CreatedByUserName,
+    DateTime CreatedAt,
+    string? PublishedByUserName,
+    DateTime? PublishedAt);

src/Jiaowu.Api/Controllers/ApprovalsController.cs

@@ -80,6 +80,9 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
     {
         var studentId = await GetStudentIdAsync(ct);
         if (studentId is null) return StudentNotFound();
+        if (!await IsStudentCourseAvailableForApplicationAsync(
+                studentId.Value, req.TeachingTaskId, ct))
+            return ConflictProblem("该课程不在您当前或已发布课表的修读课程中，请刷新课程列表后重试。");
         if (await db.CourseExemptions.AnyAsync(x => x.StudentId == studentId && x.TeachingTaskId == req.TeachingTaskId && x.Status == ApprovalStatus.Submitted, ct))
             return ConflictProblem("该课程已有免修申请在审核中。");
         var ex = new CourseExemption { StudentId = studentId.Value, TeachingTaskId = req.TeachingTaskId, Reason = req.Reason.Trim() };
@@ -141,6 +144,9 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
     {
         var sid = await GetStudentIdAsync(ct);
         if (sid is null) return StudentNotFound();
+        if (!await IsStudentCourseAvailableForApplicationAsync(
+                sid.Value, req.TeachingTaskId, ct))
+            return ConflictProblem("该课程不在您当前或已发布课表的修读课程中，请刷新课程列表后重试。");
         if (await db.DeferredExams.AnyAsync(x => x.StudentId == sid && x.TeachingTaskId == req.TeachingTaskId && x.Status == ApprovalStatus.Submitted, ct))
             return ConflictProblem("该课程已有缓考申请在审核中。");
         var d = new DeferredExam { StudentId = sid.Value, TeachingTaskId = req.TeachingTaskId, Reason = req.Reason.Trim() };
@@ -200,7 +206,9 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
             .Select(x => new { StudentName = x.GradeRecord!.Student!.Name, CourseName = x.GradeRecord.GradeSheet!.TeachingTask!.Course!.Name, x.CurrentScore, x.RequestedScore })
             .FirstAsync(ct);
         await NotificationService.SendToRoleAsync(db, SystemRoles.CollegeAdmin, "成绩修改待审核",
-            $"{gmInfo.StudentName} — 《{gmInfo.CourseName}》{gmInfo.CurrentScore}→{gmInfo.RequestedScore}", cancellationToken: ct);
+            $"{gmInfo.StudentName} — 《{gmInfo.CourseName}》{gmInfo.CurrentScore}→{gmInfo.RequestedScore}",
+            cancellationToken: ct,
+            category: NotificationCategory.Grade);
         return Created("", new { gm.Id });
     }
 
@@ -213,7 +221,14 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
         if (gm.Status != GradeModificationStatus.TeacherSubmitted) return ConflictProblem("状态不正确。");
         gm.Status = GradeModificationStatus.CollegeApproved; gm.CollegeReviewedAt = DateTime.UtcNow; gm.CollegeReviewedByUserId = scope.Current.UserId;
         await db.SaveChangesAsync(ct);
-        await NotifyRole(SystemRoles.AcademicAdmin, "成绩修改待校级审核", $"{gm.GradeRecord!.Student!.Name} — 《{gm.GradeRecord.GradeSheet!.TeachingTask!.Course!.Name}》", ct);
+        await NotificationService.SendToRoleAsync(
+            db,
+            SystemRoles.AcademicAdmin,
+            "成绩修改待校级审核",
+            $"{gm.GradeRecord!.Student!.Name} — 《{gm.GradeRecord.GradeSheet!.TeachingTask!.Course!.Name}》",
+            linkUrl: "/approvals",
+            cancellationToken: ct,
+            category: NotificationCategory.Grade);
         return NoContent();
     }
 
@@ -221,7 +236,14 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
     [Authorize(Roles = SystemRoles.SuperAdmin + "," + SystemRoles.AcademicAdmin)]
     public async Task<ActionResult> FinalApproveGradeMod(Guid id, CancellationToken ct)
     {
-        var gm = await db.GradeModifications.Include(x => x.GradeRecord).FirstOrDefaultAsync(x => x.Id == id, ct);
+        var gm = await db.GradeModifications
+            .Include(x => x.GradeRecord)
+            .ThenInclude(x => x!.Student)
+            .Include(x => x.GradeRecord)
+            .ThenInclude(x => x!.GradeSheet)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Course)
+            .FirstOrDefaultAsync(x => x.Id == id, ct);
         if (gm is null) return NotFound();
         if (gm.Status != GradeModificationStatus.CollegeApproved) return ConflictProblem("需先通过学院审核。");
         gm.Status = GradeModificationStatus.Approved; gm.FinalReviewedAt = DateTime.UtcNow; gm.FinalReviewedByUserId = scope.Current.UserId;
@@ -229,7 +251,27 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
         gm.GradeRecord!.TotalScore = gm.RequestedScore;
         gm.GradeRecord.GradePoint = GradeCalculator.CalculateGradePoint(gm.RequestedScore);
         await db.SaveChangesAsync(ct);
-        await NotificationService.SendAsync(db, gm.ApplicantUserId, "成绩修改已通过", "您的成绩修改申请已通过三级审批并生效。", cancellationToken: ct);
+        await NotificationService.SendAsync(
+            db,
+            gm.ApplicantUserId,
+            "成绩修改已通过",
+            "您的成绩修改申请已通过三级审批并生效。",
+            "/approvals",
+            ct,
+            NotificationCategory.Grade);
+        var studentUserId = gm.GradeRecord.Student?.UserId;
+        if (studentUserId.HasValue &&
+            studentUserId.Value != gm.ApplicantUserId)
+        {
+            await NotificationService.SendAsync(
+                db,
+                studentUserId.Value,
+                "成绩已更新",
+                $"《{gm.GradeRecord.GradeSheet!.TeachingTask!.Course!.Name}》成绩已由 {gm.CurrentScore} 调整为 {gm.RequestedScore}。",
+                "/grades",
+                ct,
+                NotificationCategory.Grade);
+        }
         return NoContent();
     }
 
@@ -243,17 +285,87 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
         if (gm.Status == GradeModificationStatus.TeacherSubmitted) { gm.CollegeReviewedAt = DateTime.UtcNow; gm.CollegeReviewedByUserId = scope.Current.UserId; }
         else { gm.FinalReviewedAt = DateTime.UtcNow; gm.FinalReviewedByUserId = scope.Current.UserId; }
         await db.SaveChangesAsync(ct);
-        await NotificationService.SendAsync(db, gm.ApplicantUserId, "成绩修改已驳回", gm.ReviewComment ?? "审核未通过。", cancellationToken: ct);
+        await NotificationService.SendAsync(
+            db,
+            gm.ApplicantUserId,
+            "成绩修改已驳回",
+            gm.ReviewComment ?? "审核未通过。",
+            "/approvals",
+            ct,
+            NotificationCategory.Grade);
         return NoContent();
     }
 
     // ═══════════════ Course Substitution ═══════════════
+    [HttpGet("substitutions/mine")]
+    [Authorize(Roles = SystemRoles.Student)]
+    public async Task<ActionResult> GetMySubstitutions(CancellationToken ct)
+    {
+        var sid = await GetStudentIdAsync(ct);
+        if (sid is null) return StudentNotFound();
+        return Ok(await db.CourseSubstitutions.AsNoTracking()
+            .Where(x => x.StudentId == sid)
+            .OrderByDescending(x => x.CreatedAt)
+            .Select(x => new StudentCourseSubstitutionRecord(
+                x.Id,
+                x.Status,
+                x.Reason,
+                x.ReviewComment,
+                x.SubmittedAt,
+                x.OriginalCourse!.Code,
+                x.OriginalCourse.Name,
+                x.SubstituteCourse!.Code,
+                x.SubstituteCourse.Name))
+            .ToListAsync(ct));
+    }
+
     [HttpPost("substitutions")]
     [Authorize(Roles = SystemRoles.Student)]
     public async Task<ActionResult> ApplySubstitution(SubstitutionRequest req, CancellationToken ct)
     {
         var sid = await GetStudentIdAsync(ct);
         if (sid is null) return StudentNotFound();
+        if (req.OriginalCourseId == req.SubstituteCourseId)
+            return ConflictProblem("被替代课程和替代课程不能相同。");
+        var isAssignedCourse = await db.TeachingTasks.AsNoTracking()
+            .AnyAsync(task =>
+                task.CourseId == req.OriginalCourseId &&
+                task.Status == TeachingTaskStatus.Published &&
+                !task.AcademicTerm!.IsArchived &&
+                (task.AcademicTerm.IsCurrent ||
+                 db.ScheduleEntries.Any(entry =>
+                     entry.TeachingTaskId == task.Id &&
+                     entry.SchedulePlan!.Status ==
+                         SchedulePlanStatus.Published)) &&
+                (task.Classes.Any(item =>
+                     item.AdministrativeClass!.Students.Any(student =>
+                         student.Id == sid.Value)) ||
+                 db.CourseEnrollments.Any(enrollment =>
+                     enrollment.StudentId == sid.Value &&
+                     enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                     enrollment.CourseSelectionOffering!.TeachingTaskId ==
+                         task.Id)),
+                ct);
+        var hasFailedOriginal = await db.GradeRecords.AsNoTracking()
+            .AnyAsync(record =>
+                record.StudentId == sid.Value &&
+                record.GradeSheet!.Status == GradeSheetStatus.Published &&
+                record.GradeSheet.TeachingTask!.CourseId ==
+                    req.OriginalCourseId &&
+                record.TotalScore < 60,
+                ct);
+        var canReplaceOriginal = isAssignedCourse || hasFailedOriginal;
+        if (!canReplaceOriginal)
+            return ConflictProblem("被替代课程必须是当前或已发布课表的修读课程，或已有未通过成绩的课程。");
+        var hasPassedSubstitute = await db.GradeRecords.AsNoTracking()
+            .AnyAsync(x =>
+                x.StudentId == sid.Value &&
+                x.GradeSheet!.Status == GradeSheetStatus.Published &&
+                x.GradeSheet.TeachingTask!.CourseId == req.SubstituteCourseId &&
+                x.TotalScore >= 60,
+                ct);
+        if (!hasPassedSubstitute)
+            return ConflictProblem("替代课程必须具有已发布且及格的成绩。");
         if (await db.CourseSubstitutions.AnyAsync(x => x.StudentId == sid && x.OriginalCourseId == req.OriginalCourseId && x.Status == ApprovalStatus.Submitted, ct))
             return ConflictProblem("该课程已有替代申请在审核中。");
         var cs = new CourseSubstitution { StudentId = sid.Value, OriginalCourseId = req.OriginalCourseId, SubstituteCourseId = req.SubstituteCourseId, Reason = req.Reason.Trim() };
@@ -319,16 +431,50 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
         return NoContent();
     }
 
-    // ═══════════════ Student enrolled courses ═══════════════
+    // ═══════════════ Student course options ═══════════════
     [HttpGet("my-courses")]
     [Authorize(Roles = SystemRoles.Student)]
     public async Task<ActionResult> GetMyEnrolledCourses(CancellationToken ct)
     {
         var sid = await GetStudentIdAsync(ct);
         if (sid is null) return StudentNotFound();
-        var courses = await db.CourseEnrollments.AsNoTracking()
+        var courses = await db.TeachingTasks.AsNoTracking()
-            .Where(x => x.StudentId == sid && x.Status == CourseEnrollmentStatus.Enrolled)
+            .Where(task =>
-            .Select(x => new { x.CourseSelectionOffering!.TeachingTaskId, x.CourseSelectionOffering.TeachingTask!.TaskNumber, CourseCode = x.CourseSelectionOffering.TeachingTask.Course!.Code, CourseName = x.CourseSelectionOffering.TeachingTask.Course.Name })
+                task.Status == TeachingTaskStatus.Published &&
+                !task.AcademicTerm!.IsArchived &&
+                (task.AcademicTerm.IsCurrent ||
+                 db.ScheduleEntries.Any(entry =>
+                     entry.TeachingTaskId == task.Id &&
+                     entry.SchedulePlan!.Status ==
+                         SchedulePlanStatus.Published)) &&
+                (task.Classes.Any(item =>
+                     item.AdministrativeClass!.Students.Any(student =>
+                         student.Id == sid.Value)) ||
+                 db.CourseEnrollments.Any(enrollment =>
+                     enrollment.StudentId == sid.Value &&
+                     enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                     enrollment.CourseSelectionOffering!.TeachingTaskId ==
+                         task.Id)))
+            .OrderByDescending(x => x.AcademicTerm!.IsCurrent)
+            .ThenByDescending(x => x.AcademicTerm!.StartDate)
+            .ThenBy(x => x.Course!.Code)
+            .ThenBy(x => x.TaskNumber)
+            .Select(x => new StudentApprovalCourseOption(
+                x.Id,
+                x.CourseId,
+                x.TaskNumber,
+                x.Course!.Code,
+                x.Course.Name,
+                x.Course.Credits,
+                x.AcademicTerm!.Name,
+                x.Teachers
+                    .OrderByDescending(item => item.IsPrimary)
+                    .ThenBy(item => item.Teacher!.Name)
+                    .Select(item => item.Teacher!.Name),
+                db.ScheduleEntries.Any(entry =>
+                    entry.TeachingTaskId == x.Id &&
+                    entry.SchedulePlan!.Status == SchedulePlanStatus.Published),
+                x.SchedulingMode))
             .ToListAsync(ct);
         return Ok(courses);
     }
@@ -341,8 +487,18 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
         if (sid is null) return StudentNotFound();
         var grades = await db.GradeRecords.AsNoTracking()
             .Where(x => x.StudentId == sid && x.GradeSheet!.Status == GradeSheetStatus.Published)
-            .Select(x => new { CourseId = x.GradeSheet!.TeachingTask!.CourseId, CourseCode = x.GradeSheet.TeachingTask.Course!.Code, CourseName = x.GradeSheet.TeachingTask.Course.Name, x.TotalScore, x.GradePoint, x.ExamStatus })
+            .OrderByDescending(x => x.GradeSheet!.PublishedAt)
-            .OrderBy(x => x.CourseCode)
+            .Select(x => new StudentApprovalGradeOption(
+                x.GradeSheet!.TeachingTask!.CourseId,
+                x.GradeSheet.TeachingTask.Course!.Code,
+                x.GradeSheet.TeachingTask.Course.Name,
+                x.GradeSheet.TeachingTask.Course.Credits,
+                x.TotalScore,
+                x.GradePoint,
+                x.ExamStatus,
+                x.GradeSheet.TeachingTask.AcademicTerm!.Name,
+                x.GradeSheet.TeachingTask.TaskNumber,
+                x.GradeSheet.PublishedAt))
             .ToListAsync(ct);
         return Ok(grades);
     }
@@ -377,12 +533,33 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
     }
 
     private async Task<Guid?> GetStudentIdAsync(CancellationToken ct) => await db.Students.Where(s => s.UserId == scope.Current.UserId).Select(s => (Guid?)s.Id).FirstOrDefaultAsync(ct);
+    private async Task<bool> IsStudentCourseAvailableForApplicationAsync(
+        Guid studentId,
+        Guid teachingTaskId,
+        CancellationToken ct) =>
+        await db.TeachingTasks.AsNoTracking().AnyAsync(task =>
+            task.Id == teachingTaskId &&
+            task.Status == TeachingTaskStatus.Published &&
+            !task.AcademicTerm!.IsArchived &&
+            (task.AcademicTerm.IsCurrent ||
+             db.ScheduleEntries.Any(entry =>
+                 entry.TeachingTaskId == task.Id &&
+                 entry.SchedulePlan!.Status == SchedulePlanStatus.Published)) &&
+            (task.Classes.Any(item =>
+                 item.AdministrativeClass!.Students.Any(student =>
+                     student.Id == studentId)) ||
+             db.CourseEnrollments.Any(enrollment =>
+                 enrollment.StudentId == studentId &&
+                 enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                 enrollment.CourseSelectionOffering!.TeachingTaskId ==
+                     task.Id)),
+            ct);
     private ActionResult StudentNotFound() => Conflict(new ProblemDetails { Title = "未关联学生档案", Detail = "当前账号未关联有效学生档案。", Status = 409 });
 
-    private async Task NotifyManagers(string title, string content, CancellationToken ct) { await NotificationService.SendToRoleAsync(db, SystemRoles.CollegeAdmin, title, content, cancellationToken: ct); await NotificationService.SendToRoleAsync(db, SystemRoles.AcademicAdmin, title, content, cancellationToken: ct); }
+    private async Task NotifyManagers(string title, string content, CancellationToken ct) { await NotificationService.SendToRoleAsync(db, SystemRoles.CollegeAdmin, title, content, cancellationToken: ct, category: NotificationCategory.Approval); await NotificationService.SendToRoleAsync(db, SystemRoles.AcademicAdmin, title, content, cancellationToken: ct, category: NotificationCategory.Approval); }
-    private async Task NotifyStudent(Guid sid, string title, string content, CancellationToken ct) { var uid = await db.Students.Where(s => s.Id == sid).Select(s => s.UserId).FirstOrDefaultAsync(ct); if (uid.HasValue) await NotificationService.SendAsync(db, uid.Value, title, content, cancellationToken: ct); }
+    private async Task NotifyStudent(Guid sid, string title, string content, CancellationToken ct) { var uid = await db.Students.Where(s => s.Id == sid).Select(s => s.UserId).FirstOrDefaultAsync(ct); if (uid.HasValue) await NotificationService.SendAsync(db, uid.Value, title, content, "/approvals", ct, NotificationCategory.Approval); }
-    private async Task NotifyCollege(GradeModification gm, CancellationToken ct) { await NotificationService.SendToRoleAsync(db, SystemRoles.CollegeAdmin, "成绩修改待审核", $"{gm.GradeRecord!.Student!.Name} — 《{gm.GradeRecord.GradeSheet!.TeachingTask!.Course!.Name}》{gm.CurrentScore}→{gm.RequestedScore}", cancellationToken: ct); }
+    private async Task NotifyCollege(GradeModification gm, CancellationToken ct) { await NotificationService.SendToRoleAsync(db, SystemRoles.CollegeAdmin, "成绩修改待审核", $"{gm.GradeRecord!.Student!.Name} — 《{gm.GradeRecord.GradeSheet!.TeachingTask!.Course!.Name}》{gm.CurrentScore}→{gm.RequestedScore}", cancellationToken: ct, category: NotificationCategory.Grade); }
-    private async Task NotifyRole(string role, string title, string content, CancellationToken ct) { await NotificationService.SendToRoleAsync(db, role, title, content, cancellationToken: ct); }
+    private async Task NotifyRole(string role, string title, string content, CancellationToken ct) { await NotificationService.SendToRoleAsync(db, role, title, content, cancellationToken: ct, category: NotificationCategory.Approval); }
 
     private static string SSCLabel(StudentStatusChangeType t) => t switch { StudentStatusChangeType.Suspension => "休学", StudentStatusChangeType.Resumption => "复学", StudentStatusChangeType.Withdrawal => "退学", _ => "异动" };
     private static string CALabel(CourseAdjustmentType t) => t switch { CourseAdjustmentType.Reschedule => "调课", CourseAdjustmentType.Cancel => "停课", CourseAdjustmentType.Makeup => "补课", CourseAdjustmentType.Substitute => "代课", _ => "调停课" };
@@ -390,6 +567,38 @@ public sealed class ApprovalsController(AppDbContext db, ICurrentUserDataScope s
 }
 
 public sealed record ApprovalItem(Guid Id, string Type, string Label, string Title, string Desc, DateTime Time, string College);
+public sealed record StudentApprovalCourseOption(
+    Guid TeachingTaskId,
+    Guid CourseId,
+    string TaskNumber,
+    string CourseCode,
+    string CourseName,
+    decimal Credits,
+    string AcademicTermName,
+    IEnumerable<string> TeacherNames,
+    bool HasPublishedSchedule,
+    TeachingTaskSchedulingMode SchedulingMode);
+public sealed record StudentApprovalGradeOption(
+    Guid CourseId,
+    string CourseCode,
+    string CourseName,
+    decimal Credits,
+    decimal? TotalScore,
+    decimal? GradePoint,
+    GradeExamStatus ExamStatus,
+    string AcademicTermName,
+    string TaskNumber,
+    DateTime? PublishedAt);
+public sealed record StudentCourseSubstitutionRecord(
+    Guid Id,
+    ApprovalStatus Status,
+    string Reason,
+    string? ReviewComment,
+    DateTime SubmittedAt,
+    string OriginalCourseCode,
+    string OriginalCourseName,
+    string SubstituteCourseCode,
+    string SubstituteCourseName);
 public sealed record ExemptionRequest(Guid TeachingTaskId, [Required, MaxLength(500)] string Reason);
 public sealed record GradeModRequest(Guid GradeRecordId, decimal RequestedScore, [Required, MaxLength(500)] string Reason);
 public sealed record SubstitutionRequest(Guid OriginalCourseId, Guid SubstituteCourseId, [Required, MaxLength(500)] string Reason);

src/Jiaowu.Api/Controllers/AttendanceController.cs

@@ -1,12 +1,14 @@
 using System.ComponentModel.DataAnnotations;
 using System.Security.Claims;
 using System.Security.Cryptography;
+using System.Text;
 using ClosedXML.Excel;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -48,9 +50,15 @@ public sealed class AttendanceController(
                 TermName = x.AcademicTerm!.Name,
                 CourseCode = x.Course!.Code,
                 CourseName = x.Course!.Name,
-                StudentCount = db.CourseEnrollments.Count(enrollment =>
+                StudentCount = db.Students.Count(student =>
+                    (student.Status == StudentStatus.Active &&
+                     x.Classes.Any(assignment =>
+                         assignment.AdministrativeClassId ==
+                         student.AdministrativeClassId)) ||
+                    db.CourseEnrollments.Any(enrollment =>
+                        enrollment.StudentId == student.Id &&
                         enrollment.Status == CourseEnrollmentStatus.Enrolled &&
-                    enrollment.CourseSelectionOffering!.TeachingTaskId == x.Id),
+                        enrollment.CourseSelectionOffering!.TeachingTaskId == x.Id)),
                 SheetCount = db.AttendanceSheets.Count(sheet =>
                     sheet.TeachingTaskId == x.Id)
             })
@@ -104,15 +112,13 @@ public sealed class AttendanceController(
             .FirstOrDefaultAsync(x => x.Id == request.TeachingTaskId, cancellationToken);
         if (task is null) return NotFound();
 
-        var studentIds = await db.CourseEnrollments.AsNoTracking()
+        var studentIds = await TeachingTaskRosterQuery
-            .Where(x =>
+            .ForTask(db, request.TeachingTaskId)
-                x.Status == CourseEnrollmentStatus.Enrolled &&
+            .AsNoTracking()
-                x.CourseSelectionOffering!.TeachingTaskId == request.TeachingTaskId)
+            .Select(x => x.Id)
-            .Select(x => x.StudentId)
-            .Distinct()
             .ToListAsync(cancellationToken);
         if (studentIds.Count == 0)
-            return ConflictProblem("该教学班没有有效选课学生。");
+            return ConflictProblem("该教学班没有有效学生。");
 
         var checkInMethod = request.CheckInMethod ?? AttendanceCheckInMethod.Manual;
         if (!Enum.IsDefined(checkInMethod))
@@ -175,7 +181,6 @@ public sealed class AttendanceController(
         {
             sheet.Id,
             sheet.CheckInMethod,
-            sheet.CheckInToken,
             sheet.CheckInStartsAt,
             sheet.CheckInEndsAt
         });
@@ -195,7 +200,6 @@ public sealed class AttendanceController(
                 x.AttendanceDate,
                 x.Status,
                 x.CheckInMethod,
-                x.CheckInToken,
                 x.CheckInStartsAt,
                 x.CheckInEndsAt,
                 x.TargetLatitude,
@@ -242,6 +246,103 @@ public sealed class AttendanceController(
             cancellationToken);
         var canEdit = sheet.Status == AttendanceSheetStatus.Draft && canManage;
         var now = DateTime.UtcNow;
+        var attempts = await db.AttendanceCheckInAttempts.AsNoTracking()
+            .Where(x => x.AttendanceSheetId == id)
+            .Select(x => new
+            {
+                x.StudentId,
+                x.CreatedAt,
+                x.IsSuccessful,
+                x.FailureCode,
+                x.DeviceIdentifierHash,
+                x.DevicePlatform,
+                x.IpAddress,
+                x.RiskFlags
+            })
+            .ToListAsync(cancellationToken);
+        var attemptsByStudent = attempts
+            .GroupBy(x => x.StudentId)
+            .ToDictionary(x => x.Key, x => x.OrderByDescending(a => a.CreatedAt).ToList());
+        var deviceHashes = attempts
+            .Where(x => x.IsSuccessful && x.DeviceIdentifierHash != null)
+            .Select(x => x.DeviceIdentifierHash!)
+            .Distinct(StringComparer.Ordinal)
+            .ToList();
+        var deviceReuseCounts = new Dictionary<string, int>(StringComparer.Ordinal);
+        if (deviceHashes.Count > 0)
+        {
+            var reuseRows = await db.AttendanceCheckInAttempts.AsNoTracking()
+                .Where(x =>
+                    x.IsSuccessful &&
+                    x.CreatedAt >= now.AddHours(-24) &&
+                    x.DeviceIdentifierHash != null)
+                .WhereIn(deviceHashes, x => x.DeviceIdentifierHash!)
+                .GroupBy(x => x.DeviceIdentifierHash!)
+                .Select(x => new
+                {
+                    DeviceIdentifierHash = x.Key,
+                    StudentCount = x.Select(a => a.StudentId).Distinct().Count()
+                })
+                .ToListAsync(cancellationToken);
+            deviceReuseCounts = reuseRows.ToDictionary(
+                x => x.DeviceIdentifierHash,
+                x => x.StudentCount,
+                StringComparer.Ordinal);
+        }
+
+        var responseRecords = sheet.Records.Select(r =>
+        {
+            var studentAttempts = attemptsByStudent.GetValueOrDefault(r.StudentId) ?? [];
+            var latestSuccess = studentAttempts.FirstOrDefault(x => x.IsSuccessful);
+            var riskFlags = studentAttempts
+                .SelectMany(x => ParseRiskFlags(x.RiskFlags))
+                .ToHashSet(StringComparer.Ordinal);
+            if (studentAttempts.Count(x => !x.IsSuccessful) >= 3)
+                riskFlags.Add("RepeatedFailures");
+            if (studentAttempts.Count(x => x.CreatedAt >= now.AddMinutes(-2)) >= 6)
+                riskFlags.Add("HighFrequency");
+            var sharedDeviceStudentCount = latestSuccess?.DeviceIdentifierHash is { } deviceHash
+                ? deviceReuseCounts.GetValueOrDefault(deviceHash)
+                : 0;
+            if (sharedDeviceStudentCount > 1)
+                riskFlags.Add("SharedDevice");
+            var sameIpStudentCount = latestSuccess?.IpAddress is { } ipAddress
+                ? attempts
+                    .Where(x => x.IsSuccessful && x.IpAddress == ipAddress)
+                    .Select(x => x.StudentId)
+                    .Distinct()
+                    .Count()
+                : 0;
+
+            return new
+            {
+                r.StudentId,
+                r.StudentNumber,
+                r.Name,
+                r.ClassName,
+                r.Status,
+                r.Notes,
+                r.CheckInAt,
+                r.CheckedInMethod,
+                r.CheckInAccuracyMeters,
+                r.CheckInDistanceMeters,
+                IsExempt = exemptStudentIds.Contains(r.StudentId),
+                IsDeferred = deferredStudentIds.Contains(r.StudentId),
+                CheckInAudit = latestSuccess is null
+                    ? null
+                    : new
+                    {
+                        latestSuccess.IpAddress,
+                        latestSuccess.DevicePlatform,
+                        DeviceCode = latestSuccess.DeviceIdentifierHash?[..8],
+                        SharedDeviceStudentCount = sharedDeviceStudentCount,
+                        SameIpStudentCount = sameIpStudentCount
+                    },
+                AttemptCount = studentAttempts.Count,
+                FailedAttemptCount = studentAttempts.Count(x => !x.IsSuccessful),
+                RiskFlags = riskFlags.OrderBy(x => x).ToArray()
+            };
+        }).ToList();
         return Ok(new
         {
             Sheet = new
@@ -252,7 +353,6 @@ public sealed class AttendanceController(
                 sheet.AttendanceDate,
                 sheet.Status,
                 sheet.CheckInMethod,
-                CheckInToken = canManage ? sheet.CheckInToken : null,
                 sheet.CheckInStartsAt,
                 sheet.CheckInEndsAt,
                 sheet.TargetLatitude,
@@ -271,21 +371,16 @@ public sealed class AttendanceController(
                 sheet.TaskName,
                 sheet.CourseCode,
                 sheet.CourseName,
-                Records = sheet.Records.Select(r => new
+                Records = responseRecords,
+                RiskSummary = new
                 {
-                    r.StudentId,
+                    RiskStudentCount = responseRecords.Count(x => x.RiskFlags.Length > 0),
-                    r.StudentNumber,
+                    SharedDeviceStudentCount = responseRecords.Count(
-                    r.Name,
+                        x => x.RiskFlags.Contains("SharedDevice")),
-                    r.ClassName,
+                    FrequentAttemptStudentCount = responseRecords.Count(
-                    r.Status,
+                        x => x.RiskFlags.Contains("HighFrequency") ||
-                    r.Notes,
+                             x.RiskFlags.Contains("RepeatedFailures"))
-                    r.CheckInAt,
+                }
-                    r.CheckedInMethod,
-                    r.CheckInAccuracyMeters,
-                    r.CheckInDistanceMeters,
-                    IsExempt = exemptStudentIds.Contains(r.StudentId),
-                    IsDeferred = deferredStudentIds.Contains(r.StudentId)
-                })
             },
             CanEdit = canEdit
         });
@@ -498,6 +593,39 @@ public sealed class AttendanceController(
         return NoContent();
     }
 
+    [HttpGet("sheets/{id:guid}/qr-challenge")]
+    [Authorize(Roles = AttendanceRoles)]
+    public async Task<ActionResult> GetQrChallenge(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await db.AttendanceSheets
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanManageSheet(sheet)) return Forbid();
+        if (sheet.CheckInMethod != AttendanceCheckInMethod.QrCode ||
+            string.IsNullOrWhiteSpace(sheet.CheckInToken))
+            return ConflictProblem("该考勤表不是扫码签到。");
+
+        var now = DateTime.UtcNow;
+        if (!IsCheckInOpen(
+                sheet.Status,
+                sheet.CheckInMethod,
+                sheet.CheckInStartsAt,
+                sheet.CheckInEndsAt,
+                now))
+            return ConflictProblem("签到尚未开始或已经结束。");
+
+        var challenge = AttendanceCheckInChallenge.Create(
+            sheet.Id,
+            sheet.CheckInToken,
+            now);
+        return Ok(challenge);
+    }
+
     // ═══════════════ Student endpoints ═══════════════
 
     [HttpGet("check-in-info")]
@@ -511,11 +639,13 @@ public sealed class AttendanceController(
             return ConflictProblem("当前账号未关联学生档案。");
         if (string.IsNullOrWhiteSpace(token))
             return NotFound();
+        if (!AttendanceCheckInChallenge.TryReadSheetId(token, out var sheetId))
+            return NotFound();
 
         var activity = await db.AttendanceRecords.AsNoTracking()
             .Where(x =>
                 x.StudentId == studentId.Value &&
-                x.AttendanceSheet!.CheckInToken == token.Trim())
+                x.AttendanceSheetId == sheetId)
             .Select(x => new
             {
                 SheetId = x.AttendanceSheetId,
@@ -525,6 +655,7 @@ public sealed class AttendanceController(
                 x.AttendanceSheet.CheckInMethod,
                 x.AttendanceSheet.CheckInStartsAt,
                 x.AttendanceSheet.CheckInEndsAt,
+                x.AttendanceSheet.CheckInToken,
                 CourseCode = x.AttendanceSheet.TeachingTask!.Course!.Code,
                 CourseName = x.AttendanceSheet.TeachingTask.Course.Name,
                 TaskNumber = x.AttendanceSheet.TeachingTask.TaskNumber,
@@ -534,6 +665,13 @@ public sealed class AttendanceController(
         if (activity is null) return NotFound();
 
         var now = DateTime.UtcNow;
+        if (activity.CheckInMethod != AttendanceCheckInMethod.QrCode ||
+            !AttendanceCheckInChallenge.IsValid(
+                token,
+                activity.SheetId,
+                activity.CheckInToken,
+                now))
+            return NotFound();
         return Ok(new
         {
             activity.SheetId,
@@ -605,8 +743,11 @@ public sealed class AttendanceController(
             .Where(x => x.StudentId == studentId.Value);
         if (!string.IsNullOrWhiteSpace(request.Token))
         {
-            var token = request.Token.Trim();
+            if (!AttendanceCheckInChallenge.TryReadSheetId(
-            source = source.Where(x => x.AttendanceSheet!.CheckInToken == token);
+                    request.Token.Trim(),
+                    out var tokenSheetId))
+                return NotFound();
+            source = source.Where(x => x.AttendanceSheetId == tokenSheetId);
         }
         else if (request.AttendanceSheetId.HasValue)
         {
@@ -622,8 +763,59 @@ public sealed class AttendanceController(
         if (record?.AttendanceSheet is null) return NotFound();
         var sheet = record.AttendanceSheet;
         var now = DateTime.UtcNow;
+
+        async Task<ActionResult> RejectAttemptAsync(
+            string failureCode,
+            string detail,
+            double? distanceMeters = null)
+        {
+            await AddCheckInAttemptAsync(
+                sheet,
+                studentId.Value,
+                request,
+                false,
+                failureCode,
+                distanceMeters,
+                now,
+                cancellationToken);
+            await db.SaveChangesAsync(cancellationToken);
+            return ConflictProblem(detail);
+        }
+
+        if (sheet.CheckInMethod == AttendanceCheckInMethod.QrCode &&
+            !AttendanceCheckInChallenge.IsValid(
+                request.Token,
+                sheet.Id,
+                sheet.CheckInToken,
+                now))
+            return await RejectAttemptAsync(
+                "InvalidQrChallenge",
+                "签到二维码已失效，请重新扫描教师当前展示的二维码。");
+        if (!IsCheckInOpen(
+                sheet.Status,
+                sheet.CheckInMethod,
+                sheet.CheckInStartsAt,
+                sheet.CheckInEndsAt,
+                now))
+            return await RejectAttemptAsync(
+                "CheckInClosed",
+                "签到尚未开始或已经结束。");
+        if (sheet.CheckInMethod == AttendanceCheckInMethod.Manual)
+            return await RejectAttemptAsync(
+                "ManualSheet",
+                "该考勤表不支持学生在线签到。");
         if (record.CheckInAt.HasValue)
         {
+            await AddCheckInAttemptAsync(
+                sheet,
+                studentId.Value,
+                request,
+                true,
+                null,
+                record.CheckInDistanceMeters,
+                now,
+                cancellationToken);
+            await db.SaveChangesAsync(cancellationToken);
             return Ok(new
             {
                 AlreadyCheckedIn = true,
@@ -631,37 +823,35 @@ public sealed class AttendanceController(
                 record.CheckInDistanceMeters
             });
         }
-        if (!IsCheckInOpen(
-                sheet.Status,
-                sheet.CheckInMethod,
-                sheet.CheckInStartsAt,
-                sheet.CheckInEndsAt,
-                now))
-            return ConflictProblem("签到尚未开始或已经结束。");
-        if (sheet.CheckInMethod == AttendanceCheckInMethod.Manual)
-            return ConflictProblem("该考勤表不支持学生在线签到。");
 
         double? distanceMeters = null;
-        if (sheet.CheckInMethod == AttendanceCheckInMethod.QrCode)
+        if (sheet.CheckInMethod == AttendanceCheckInMethod.Location)
-        {
-            if (string.IsNullOrWhiteSpace(request.Token) ||
-                !string.Equals(
-                    sheet.CheckInToken,
-                    request.Token.Trim(),
-                    StringComparison.Ordinal))
-                return NotFound();
-        }
-        else if (sheet.CheckInMethod == AttendanceCheckInMethod.Location)
         {
             if (request.Latitude is < -90 or > 90 ||
                 request.Longitude is < -180 or > 180 ||
                 request.Latitude is null ||
                 request.Longitude is null)
-                return ConflictProblem("未获取到有效的当前位置。");
+                return await RejectAttemptAsync(
+                    "InvalidLocation",
+                    "未获取到有效的当前位置。");
             if (sheet.TargetLatitude is null ||
                 sheet.TargetLongitude is null ||
                 sheet.LocationRadiusMeters is null)
-                return ConflictProblem("签到活动没有配置有效的位置范围。");
+                return await RejectAttemptAsync(
+                    "LocationNotConfigured",
+                    "签到活动没有配置有效的位置范围。");
+            var maximumAllowedAccuracyMeters = Math.Min(
+                100d,
+                sheet.LocationRadiusMeters.Value);
+            if (request.AccuracyMeters is null ||
+                !double.IsFinite(request.AccuracyMeters.Value) ||
+                request.AccuracyMeters <= 0 ||
+                request.AccuracyMeters > maximumAllowedAccuracyMeters)
+            {
+                return await RejectAttemptAsync(
+                    "InsufficientAccuracy",
+                    $"当前定位精度不足，请在精度达到 {Math.Round(maximumAllowedAccuracyMeters)} 米以内后重试。");
+            }
 
             distanceMeters = CalculateDistanceMeters(
                 (double)sheet.TargetLatitude.Value,
@@ -670,8 +860,10 @@ public sealed class AttendanceController(
                 (double)request.Longitude.Value);
             if (distanceMeters > sheet.LocationRadiusMeters.Value)
             {
-                return ConflictProblem(
+                return await RejectAttemptAsync(
-                    $"当前位置距签到点约 {Math.Round(distanceMeters.Value)} 米，超出 {sheet.LocationRadiusMeters.Value} 米签到范围。");
+                    "OutsideGeofence",
+                    $"当前位置距签到点约 {Math.Round(distanceMeters.Value)} 米，超出 {sheet.LocationRadiusMeters.Value} 米签到范围。",
+                    distanceMeters);
             }
         }
 
@@ -688,6 +880,15 @@ public sealed class AttendanceController(
             ? request.AccuracyMeters
             : null;
         record.CheckInDistanceMeters = distanceMeters;
+        await AddCheckInAttemptAsync(
+            sheet,
+            studentId.Value,
+            request,
+            true,
+            null,
+            distanceMeters,
+            now,
+            cancellationToken);
         await db.SaveChangesAsync(cancellationToken);
 
         return Ok(new
@@ -793,7 +994,8 @@ public sealed class AttendanceController(
             await NotificationService.SendToUserIdsAsync(db, teacherUserIds,
                 "考勤申诉待处理",
                 $"学生 {studentName} 对《{courseName}》考勤记录提出申诉。",
-                "/teacher-attendance", cancellationToken);
+                "/teacher-attendance", cancellationToken,
+                NotificationCategory.Attendance);
         }
 
         return NoContent();
@@ -905,7 +1107,7 @@ public sealed class AttendanceController(
                 request.Comment is not null
                     ? $"您的考勤申诉{result}。意见：{request.Comment}"
                     : $"您的考勤申诉{result}。",
-                null, cancellationToken);
+                null, cancellationToken, NotificationCategory.Attendance);
         }
 
         return NoContent();
@@ -980,6 +1182,103 @@ public sealed class AttendanceController(
             .FirstOrDefaultAsync(cancellationToken);
     }
 
+    private async Task AddCheckInAttemptAsync(
+        AttendanceSheet sheet,
+        Guid studentId,
+        AttendanceCheckInRequest request,
+        bool isSuccessful,
+        string? failureCode,
+        double? distanceMeters,
+        DateTime now,
+        CancellationToken cancellationToken)
+    {
+        var deviceIdentifierHash = HashDeviceIdentifier(request.DeviceId);
+        var riskFlags = new HashSet<string>(StringComparer.Ordinal);
+        if (deviceIdentifierHash is null)
+        {
+            riskFlags.Add("MissingDeviceId");
+        }
+        else if (await db.AttendanceCheckInAttempts.AsNoTracking().AnyAsync(
+                     x =>
+                         x.IsSuccessful &&
+                         x.StudentId != studentId &&
+                         x.DeviceIdentifierHash == deviceIdentifierHash &&
+                         x.CreatedAt >= now.AddHours(-24),
+                     cancellationToken))
+        {
+            riskFlags.Add("SharedDevice");
+        }
+
+        var recentAttemptCount = await db.AttendanceCheckInAttempts.AsNoTracking()
+            .CountAsync(
+                x => x.StudentId == studentId &&
+                     x.CreatedAt >= now.AddMinutes(-2),
+                cancellationToken);
+        if (recentAttemptCount >= 5)
+            riskFlags.Add("HighFrequency");
+
+        if (!isSuccessful)
+        {
+            var recentFailureCount = await db.AttendanceCheckInAttempts.AsNoTracking()
+                .CountAsync(
+                    x => x.StudentId == studentId &&
+                         !x.IsSuccessful &&
+                         x.CreatedAt >= now.AddMinutes(-5),
+                    cancellationToken);
+            if (recentFailureCount >= 2)
+                riskFlags.Add("RepeatedFailures");
+        }
+
+        var context = ControllerContext.HttpContext;
+        db.AttendanceCheckInAttempts.Add(new AttendanceCheckInAttempt
+        {
+            AttendanceSheetId = sheet.Id,
+            StudentId = studentId,
+            CheckInMethod = sheet.CheckInMethod,
+            IsSuccessful = isSuccessful,
+            FailureCode = failureCode,
+            DeviceIdentifierHash = deviceIdentifierHash,
+            DevicePlatform = Limit(Normalize(request.DevicePlatform), 32),
+            IpAddress = Limit(
+                context?.Connection.RemoteIpAddress?.ToString(),
+                64),
+            UserAgent = Limit(
+                context?.Request.Headers.UserAgent.ToString(),
+                500),
+            RiskFlags = riskFlags.Count == 0
+                ? null
+                : string.Join(',', riskFlags.OrderBy(x => x)),
+            Latitude = request.Latitude,
+            Longitude = request.Longitude,
+            AccuracyMeters = request.AccuracyMeters,
+            DistanceMeters = distanceMeters,
+            CreatedAt = now,
+            UpdatedAt = now
+        });
+    }
+
+    private static string? HashDeviceIdentifier(string? deviceId)
+    {
+        var normalized = Normalize(deviceId)?.ToLowerInvariant();
+        return normalized is null
+            ? null
+            : Convert.ToHexString(
+                SHA256.HashData(Encoding.UTF8.GetBytes(normalized)));
+    }
+
+    private static IEnumerable<string> ParseRiskFlags(string? value) =>
+        string.IsNullOrWhiteSpace(value)
+            ? []
+            : value.Split(
+                ',',
+                StringSplitOptions.RemoveEmptyEntries |
+                StringSplitOptions.TrimEntries);
+
+    private static string? Limit(string? value, int maximumLength) =>
+        value is null || value.Length <= maximumLength
+            ? value
+            : value[..maximumLength];
+
     private static bool IsCheckInOpen(
         AttendanceSheetStatus status,
         AttendanceCheckInMethod method,
@@ -1031,16 +1330,14 @@ public sealed class AttendanceController(
             .FirstOrDefaultAsync(cancellationToken);
         if (course is null) return null;
 
-        var enrolledStudents = await db.CourseEnrollments.AsNoTracking()
+        var enrolledStudents = await TeachingTaskRosterQuery
-            .Where(x =>
+            .ForTask(db, teachingTaskId)
-                x.Status == CourseEnrollmentStatus.Enrolled &&
+            .AsNoTracking()
-                x.CourseSelectionOffering!.TeachingTaskId == teachingTaskId)
             .Select(x => new AttendanceStatisticsStudentIdentity(
-                x.StudentId,
+                x.Id,
-                x.Student!.StudentNumber,
+                x.StudentNumber,
-                x.Student.Name,
+                x.Name,
-                x.Student.AdministrativeClass!.Name))
+                x.AdministrativeClass!.Name))
-            .Distinct()
             .ToListAsync(cancellationToken);
 
         var submittedSheets = await db.AttendanceSheets.AsNoTracking()
@@ -1376,7 +1673,9 @@ public sealed record AttendanceCheckInRequest(
     [MaxLength(64)] string? Token,
     [Range(-90, 90)] decimal? Latitude,
     [Range(-180, 180)] decimal? Longitude,
-    [Range(0, 5000)] double? AccuracyMeters);
+    [Range(0, 5000)] double? AccuracyMeters,
+    [MaxLength(128)] string? DeviceId = null,
+    [MaxLength(32)] string? DevicePlatform = null);
 
 public sealed record AttendanceCourseStatistics(
     AttendanceStatisticsCourse Course,

src/Jiaowu.Api/Controllers/AuthController.cs

@@ -3,6 +3,7 @@ using System.Security.Claims;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Identity;
@@ -17,35 +18,51 @@ namespace Jiaowu.Api.Controllers;
 public sealed class AuthController(
     AppDbContext db,
     UserManager<ApplicationUser> userManager,
-    ITokenService tokenService) : ControllerBase
+    ITokenService tokenService,
+    IAppCache cache) : ControllerBase
 {
     [AllowAnonymous]
     [HttpGet("activation-options")]
     public async Task<ActionResult> GetActivationOptions(CancellationToken cancellationToken)
+    {
+        var result = await cache.GetOrCreateAsync(
+            AppCacheKeys.ActivationOptions,
+            async token =>
             {
                 var colleges = await db.Colleges.AsNoTracking()
                     .Where(x => x.IsEnabled)
                     .OrderBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name })
+                    .Select(x => new ActivationCollegeOption(x.Id, x.Code, x.Name))
-            .ToListAsync(cancellationToken);
+                    .ToListAsync(token);
                 var majors = await db.Majors.AsNoTracking()
                     .Where(x => x.IsEnabled && x.College!.IsEnabled)
                     .OrderBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name, x.CollegeId })
+                    .Select(x => new ActivationMajorOption(
-            .ToListAsync(cancellationToken);
+                        x.Id, x.Code, x.Name, x.CollegeId))
+                    .ToListAsync(token);
                 var classes = await db.AdministrativeClasses.AsNoTracking()
-            .Where(x => x.IsEnabled && x.Major!.IsEnabled && x.Major.College!.IsEnabled)
+                    .Where(x =>
+                        x.IsEnabled &&
+                        x.Major!.IsEnabled &&
+                        x.Major.College!.IsEnabled)
                     .OrderByDescending(x => x.Grade)
                     .ThenBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name, x.Grade, x.MajorId })
+                    .Select(x => new ActivationClassOption(
-            .ToListAsync(cancellationToken);
+                        x.Id, x.Code, x.Name, x.Grade, x.MajorId))
-        return Ok(new
+                    .ToListAsync(token);
-        {
+                return new ActivationOptionsResponse(
-            Colleges = colleges,
+                    colleges,
-            Majors = majors,
+                    majors,
-            Classes = classes,
+                    classes,
-            Grades = classes.Select(x => x.Grade).Distinct().OrderByDescending(x => x)
+                    classes.Select(x => x.Grade)
-        });
+                        .Distinct()
+                        .OrderByDescending(x => x)
+                        .ToList());
+            },
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
     }
 
     [AllowAnonymous]
@@ -219,3 +236,24 @@ public sealed record CurrentUserResponse(
     IEnumerable<string> Roles,
     Guid? CollegeId,
     string EffectiveDataScope);
+
+public sealed record ActivationOptionsResponse(
+    IReadOnlyList<ActivationCollegeOption> Colleges,
+    IReadOnlyList<ActivationMajorOption> Majors,
+    IReadOnlyList<ActivationClassOption> Classes,
+    IReadOnlyList<int> Grades);
+
+public sealed record ActivationCollegeOption(Guid Id, string Code, string Name);
+
+public sealed record ActivationMajorOption(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid CollegeId);
+
+public sealed record ActivationClassOption(
+    Guid Id,
+    string Code,
+    string Name,
+    int Grade,
+    Guid MajorId);

src/Jiaowu.Api/Controllers/BaseDataController.cs

@@ -2,6 +2,7 @@ using System.ComponentModel.DataAnnotations;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Common;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
@@ -12,7 +13,7 @@ namespace Jiaowu.Api.Controllers;
 [ApiController]
 [Authorize]
 [Route("api/base-data")]
-public sealed class BaseDataController(AppDbContext db) : ControllerBase
+public sealed class BaseDataController(AppDbContext db, IAppCache cache) : ControllerBase
 {
     private const string Administrators =
         $"{SystemRoles.SuperAdmin},{SystemRoles.AcademicAdmin}";
@@ -20,9 +21,14 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
     [HttpGet("campuses")]
     public async Task<ActionResult<IReadOnlyCollection<Campus>>> GetCampuses(
         CancellationToken cancellationToken) =>
-        await db.Campuses.AsNoTracking()
+        await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("campuses"),
+            token => db.Campuses.AsNoTracking()
                 .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .ToListAsync(cancellationToken);
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
 
     [HttpPost("campuses")]
     [Authorize(Roles = Administrators)]
@@ -52,21 +58,32 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         if (entity is null) return NotFound();
         ApplyCatalog(entity, request);
         entity.Address = request.Description?.Trim();
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("colleges")]
-    public async Task<ActionResult<object>> GetColleges(CancellationToken cancellationToken) =>
+    public async Task<ActionResult<object>> GetColleges(CancellationToken cancellationToken)
-        Ok(await db.Colleges.AsNoTracking()
-            .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .Select(x => new
     {
-                x.Id, x.Code, x.Name, x.ShortName, x.CampusId,
+        var result = await cache.GetOrCreateAsync(
-                CampusName = x.Campus != null ? x.Campus.Name : null,
+            AppCacheKeys.BaseData("colleges"),
-                x.IsEnabled, x.SortOrder
+            token => db.Colleges.AsNoTracking()
-            })
+                .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .ToListAsync(cancellationToken));
+                .Select(x => new CollegeListItem(
+                    x.Id,
+                    x.Code,
+                    x.Name,
+                    x.ShortName,
+                    x.CampusId,
+                    x.Campus != null ? x.Campus.Name : null,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpPost("colleges")]
     [Authorize(Roles = Administrators)]
@@ -104,29 +121,46 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         ApplyCatalog(entity, request);
         entity.ShortName = request.ShortName?.Trim();
         entity.CampusId = request.CampusId;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("majors")]
-    public async Task<ActionResult<object>> GetMajors(CancellationToken cancellationToken) =>
+    public async Task<ActionResult<object>> GetMajors(CancellationToken cancellationToken)
-        Ok(await db.Majors.AsNoTracking()
-            .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .Select(x => new
     {
-                x.Id, x.Code, x.Name, x.CollegeId,
+        var result = await cache.GetOrCreateAsync(
-                CollegeName = x.College!.Name,
+            AppCacheKeys.BaseData("majors"),
-                x.DegreeType, x.SchoolingYears, x.IsEnabled, x.SortOrder
+            token => db.Majors.AsNoTracking()
-            })
+                .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .ToListAsync(cancellationToken));
+                .Select(x => new MajorListItem(
+                    x.Id,
+                    x.Code,
+                    x.Name,
+                    x.CollegeId,
+                    x.College!.Name,
+                    x.DegreeType,
+                    x.SchoolingYears,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpGet("course-categories")]
     public async Task<ActionResult<IReadOnlyCollection<CourseCategory>>> GetCourseCategories(
         CancellationToken cancellationToken) =>
-        await db.CourseCategories.AsNoTracking()
+        await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("course-categories"),
+            token => db.CourseCategories.AsNoTracking()
                 .OrderBy(x => x.SortOrder)
                 .ThenBy(x => x.Code)
-            .ToListAsync(cancellationToken);
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
 
     [HttpPost("course-categories")]
     [Authorize(Roles = Administrators)]
@@ -154,7 +188,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         var entity = await db.CourseCategories.FindAsync([id], cancellationToken);
         if (entity is null) return NotFound();
         ApplyCatalog(entity, request);
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -193,23 +227,35 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         entity.CollegeId = request.CollegeId;
         entity.DegreeType = request.DegreeType.Trim();
         entity.SchoolingYears = request.SchoolingYears;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("classes")]
-    public async Task<ActionResult<object>> GetClasses(CancellationToken cancellationToken) =>
+    public async Task<ActionResult<object>> GetClasses(CancellationToken cancellationToken)
-        Ok(await db.AdministrativeClasses.AsNoTracking()
-            .OrderByDescending(x => x.Grade).ThenBy(x => x.Code)
-            .Select(x => new
     {
-                x.Id, x.Code, x.Name, x.MajorId,
+        var result = await cache.GetOrCreateAsync(
-                MajorName = x.Major!.Name,
+            AppCacheKeys.BaseData("classes"),
-                CollegeName = x.Major.College!.Name,
+            token => db.AdministrativeClasses.AsNoTracking()
-                x.Grade, x.CounselorUserId, x.CounselorName,
+                .OrderByDescending(x => x.Grade).ThenBy(x => x.Code)
-                x.IsEnabled, x.SortOrder
+                .Select(x => new AdministrativeClassListItem(
-            })
+                    x.Id,
-            .ToListAsync(cancellationToken));
+                    x.Code,
+                    x.Name,
+                    x.MajorId,
+                    x.Major!.Name,
+                    x.Major.College!.Name,
+                    x.Grade,
+                    x.CounselorUserId,
+                    x.CounselorName,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpGet("counselors")]
     [Authorize(Roles = Administrators)]
@@ -279,18 +325,23 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         entity.Grade = request.Grade;
         entity.CounselorUserId = request.CounselorUserId;
         entity.CounselorName = counselorName;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("terms")]
     public async Task<ActionResult<IReadOnlyCollection<AcademicTerm>>> GetTerms(
         CancellationToken cancellationToken) =>
-        await db.AcademicTerms.AsNoTracking()
+        await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("terms"),
+            token => db.AcademicTerms.AsNoTracking()
                 .OrderByDescending(x => x.IsCurrent)
                 .ThenBy(x => x.IsArchived)
                 .ThenByDescending(x => x.StartDate)
-            .ToListAsync(cancellationToken);
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
 
     [HttpPost("terms")]
     [Authorize(Roles = Administrators)]
@@ -360,7 +411,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         entity.StartDate = request.StartDate;
         entity.EndDate = request.EndDate;
         entity.IsCurrent = request.IsCurrent;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -384,7 +435,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         foreach (var currentTerm in currentTerms)
             currentTerm.IsCurrent = false;
         entity.IsCurrent = true;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -402,7 +453,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
 
         entity.IsArchived = true;
         entity.ArchivedAt = DateTime.UtcNow;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -418,35 +469,59 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
 
         entity.IsArchived = false;
         entity.ArchivedAt = null;
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
     [HttpGet("classrooms")]
-    public async Task<ActionResult<object>> GetClassrooms(CancellationToken cancellationToken) =>
+    public async Task<ActionResult<object>> GetClassrooms(CancellationToken cancellationToken)
-        Ok(await db.Classrooms.AsNoTracking()
+    {
+        var result = await cache.GetOrCreateAsync(
+            AppCacheKeys.BaseData("classrooms"),
+            token => db.Classrooms.AsNoTracking()
                 .OrderBy(x => x.Building!.Campus!.SortOrder)
                 .ThenBy(x => x.Code)
-            .Select(x => new
+                .Select(x => new ClassroomListItem(
-            {
+                    x.Id,
-                x.Id, x.Code, x.Name, x.BuildingId,
+                    x.Code,
-                CampusId = x.Building!.CampusId,
+                    x.Name,
-                BuildingName = x.Building!.Name,
+                    x.BuildingId,
-                CampusName = x.Building.Campus!.Name,
+                    x.Building!.CampusId,
-                x.Capacity, x.RoomType, x.Equipment, x.IsEnabled, x.SortOrder
+                    x.Building.Name,
-            })
+                    x.Building.Campus!.Name,
-            .ToListAsync(cancellationToken));
+                    x.Capacity,
+                    x.RoomType,
+                    x.Equipment,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpGet("buildings")]
-    public async Task<ActionResult<object>> GetBuildings(CancellationToken cancellationToken) =>
+    public async Task<ActionResult<object>> GetBuildings(CancellationToken cancellationToken)
-        Ok(await db.Buildings.AsNoTracking()
-            .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
-            .Select(x => new
     {
-                x.Id, x.Code, x.Name, x.CampusId,
+        var result = await cache.GetOrCreateAsync(
-                CampusName = x.Campus!.Name, x.IsEnabled, x.SortOrder
+            AppCacheKeys.BaseData("buildings"),
-            })
+            token => db.Buildings.AsNoTracking()
-            .ToListAsync(cancellationToken));
+                .OrderBy(x => x.SortOrder).ThenBy(x => x.Code)
+                .Select(x => new BuildingListItem(
+                    x.Id,
+                    x.Code,
+                    x.Name,
+                    x.CampusId,
+                    x.Campus!.Name,
+                    x.IsEnabled,
+                    x.SortOrder))
+                .ToListAsync(token),
+            AppCacheProfile.ReferenceData,
+            [AppCacheTags.BaseData],
+            cancellationToken);
+        return Ok(result);
+    }
 
     [HttpPost("buildings")]
     [Authorize(Roles = Administrators)]
@@ -503,7 +578,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         entity.Capacity = request.Capacity;
         entity.RoomType = request.RoomType.Trim();
         entity.Equipment = request.Equipment?.Trim();
-        await db.SaveChangesAsync(cancellationToken);
+        await SaveAndInvalidateAsync(cancellationToken);
         return entity;
     }
 
@@ -533,7 +608,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         db.Remove(entity);
         try
         {
-            await db.SaveChangesAsync(cancellationToken);
+            await SaveAndInvalidateAsync(cancellationToken);
             return NoContent();
         }
         catch (DbUpdateException)
@@ -556,7 +631,7 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         db.Add(entity);
         try
         {
-            await db.SaveChangesAsync(cancellationToken);
+            await SaveAndInvalidateAsync(cancellationToken);
         }
         catch (DbUpdateException)
         {
@@ -566,6 +641,12 @@ public sealed class BaseDataController(AppDbContext db) : ControllerBase
         return CreatedAtAction(action, new { id = entity.Id }, entity);
     }
 
+    private async Task SaveAndInvalidateAsync(CancellationToken cancellationToken)
+    {
+        await db.SaveChangesAsync(cancellationToken);
+        await cache.RemoveByTagAsync(AppCacheTags.BaseData, cancellationToken);
+    }
+
     private async Task<string?> GetCounselorNameAsync(
         Guid? userId,
         CancellationToken cancellationToken)
@@ -649,3 +730,60 @@ public sealed record ClassroomRequest(
     [Required, MaxLength(40)] string RoomType,
     [MaxLength(300)] string? Equipment)
     : CatalogRequest(Code, Name, SortOrder, IsEnabled);
+
+public sealed record CollegeListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    string? ShortName,
+    Guid? CampusId,
+    string? CampusName,
+    bool IsEnabled,
+    int SortOrder);
+
+public sealed record MajorListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid CollegeId,
+    string CollegeName,
+    string DegreeType,
+    int SchoolingYears,
+    bool IsEnabled,
+    int SortOrder);
+
+public sealed record AdministrativeClassListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid MajorId,
+    string MajorName,
+    string CollegeName,
+    int Grade,
+    Guid? CounselorUserId,
+    string? CounselorName,
+    bool IsEnabled,
+    int SortOrder);
+
+public sealed record BuildingListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid CampusId,
+    string CampusName,
+    bool IsEnabled,
+    int SortOrder);
+
+public sealed record ClassroomListItem(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid BuildingId,
+    Guid CampusId,
+    string BuildingName,
+    string CampusName,
+    int Capacity,
+    string RoomType,
+    string? Equipment,
+    bool IsEnabled,
+    int SortOrder);

src/Jiaowu.Api/Controllers/BaseDataExcelController.cs

@@ -1,6 +1,7 @@
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Common;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
@@ -12,7 +13,7 @@ namespace Jiaowu.Api.Controllers;
 [ApiController]
 [Authorize(Roles = Administrators)]
 [Route("api/base-data")]
-public sealed class BaseDataExcelController(AppDbContext db) : ControllerBase
+public sealed class BaseDataExcelController(AppDbContext db, IAppCache cache) : ControllerBase
 {
     private const string Administrators =
         $"{SystemRoles.SuperAdmin},{SystemRoles.AcademicAdmin}";
@@ -114,6 +115,9 @@ public sealed class BaseDataExcelController(AppDbContext db) : ControllerBase
 
                     await db.SaveChangesAsync(cancellationToken);
                     await transaction.CommitAsync(cancellationToken);
+                    await cache.RemoveByTagAsync(
+                        AppCacheTags.BaseData,
+                        cancellationToken);
                     return Ok(result);
                 }
                 catch (DbUpdateException)

src/Jiaowu.Api/Controllers/ClassroomReservationsController.cs

@@ -0,0 +1,708 @@
+using System.ComponentModel.DataAnnotations;
+using System.Data;
+using Jiaowu.Api.Contracts;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Timetables;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Controllers;
+
+[ApiController]
+[Authorize]
+[Route("api/classroom-reservations")]
+public sealed class ClassroomReservationsController(
+    AppDbContext db,
+    ICurrentUserDataScope scope,
+    ClassroomReservationAvailabilityService availabilityService) : ControllerBase
+{
+    [HttpGet("options")]
+    public async Task<ActionResult> GetOptions(
+        Guid? academicTermId,
+        CancellationToken cancellationToken)
+    {
+        var applicant = await ResolveApplicantAsync(cancellationToken);
+        var terms = await db.AcademicTerms.AsNoTracking()
+            .Where(term => term.IsEnabled && !term.IsArchived)
+            .OrderByDescending(term => term.IsCurrent)
+            .ThenByDescending(term => term.StartDate)
+            .Select(term => new
+            {
+                term.Id,
+                term.Name,
+                term.StartDate,
+                term.EndDate,
+                term.IsCurrent,
+                HasPublishedTimetable = db.SchedulePlans.Any(plan =>
+                    plan.AcademicTermId == term.Id &&
+                    plan.Status == SchedulePlanStatus.Published)
+            })
+            .ToListAsync(cancellationToken);
+        var selectedTermId = academicTermId
+            ?? terms.FirstOrDefault(term =>
+                term.IsCurrent && term.HasPublishedTimetable)?.Id
+            ?? terms.FirstOrDefault(term => term.HasPublishedTimetable)?.Id
+            ?? terms.FirstOrDefault()?.Id;
+        var campuses = await db.Campuses.AsNoTracking()
+            .Where(campus => campus.IsEnabled)
+            .OrderBy(campus => campus.SortOrder)
+            .ThenBy(campus => campus.Code)
+            .Select(campus => new { campus.Id, campus.Code, campus.Name })
+            .ToListAsync(cancellationToken);
+        var buildings = await db.Buildings.AsNoTracking()
+            .Where(building =>
+                building.IsEnabled &&
+                building.Campus!.IsEnabled)
+            .OrderBy(building => building.Campus!.SortOrder)
+            .ThenBy(building => building.SortOrder)
+            .ThenBy(building => building.Code)
+            .Select(building => new
+            {
+                building.Id,
+                building.Code,
+                building.Name,
+                building.CampusId
+            })
+            .ToListAsync(cancellationToken);
+        var classrooms = await db.Classrooms.AsNoTracking()
+            .Where(classroom =>
+                classroom.IsEnabled &&
+                classroom.Building!.IsEnabled &&
+                classroom.Building.Campus!.IsEnabled)
+            .OrderBy(classroom => classroom.Building!.Campus!.SortOrder)
+            .ThenBy(classroom => classroom.Building!.SortOrder)
+            .ThenBy(classroom => classroom.Code)
+            .Select(classroom => new
+            {
+                classroom.Id,
+                classroom.Code,
+                classroom.Name,
+                classroom.BuildingId,
+                classroom.Capacity,
+                classroom.RoomType
+            })
+            .ToListAsync(cancellationToken);
+        var timeSlots = await LoadTimeSlotsAsync(
+            selectedTermId,
+            cancellationToken);
+
+        return Ok(new
+        {
+            Applicant = applicant.Context is null
+                ? null
+                : new
+                {
+                    applicant.Context.User.Id,
+                    applicant.Context.User.DisplayName,
+                    CollegeId = applicant.Context.CollegeId,
+                    CollegeName = applicant.Context.CollegeName
+                },
+            ApplicantProblem = applicant.Error,
+            Terms = terms,
+            SelectedTermId = selectedTermId,
+            Campuses = campuses,
+            Buildings = buildings,
+            Classrooms = classrooms,
+            TimeSlots = timeSlots
+        });
+    }
+
+    [HttpGet("availability")]
+    public async Task<ActionResult> GetAvailability(
+        Guid academicTermId,
+        DateOnly reservationDate,
+        [Range(1, 30)] int startPeriod,
+        [Range(1, 6)] int periodCount,
+        Guid? campusId,
+        Guid? buildingId,
+        [Range(1, 10000)] int? attendeeCount,
+        CancellationToken cancellationToken)
+    {
+        var validation = await ValidateSlotAsync(
+            academicTermId,
+            reservationDate,
+            startPeriod,
+            periodCount,
+            cancellationToken);
+        if (validation.Error is not null) return validation.Error;
+
+        var occupiedIds = await availabilityService.GetOccupiedClassroomIdsAsync(
+            validation.Term!,
+            reservationDate,
+            startPeriod,
+            periodCount,
+            null,
+            cancellationToken);
+        var rooms = db.Classrooms.AsNoTracking()
+            .Where(classroom =>
+                classroom.IsEnabled &&
+                classroom.Building!.IsEnabled &&
+                classroom.Building.Campus!.IsEnabled)
+            .WhereNotIn(occupiedIds, classroom => classroom.Id);
+        if (campusId.HasValue)
+            rooms = rooms.Where(room =>
+                room.Building!.CampusId == campusId.Value);
+        if (buildingId.HasValue)
+            rooms = rooms.Where(room => room.BuildingId == buildingId.Value);
+        if (attendeeCount.HasValue)
+            rooms = rooms.Where(room => room.Capacity >= attendeeCount.Value);
+
+        var items = await rooms
+            .OrderBy(room => room.Building!.Campus!.SortOrder)
+            .ThenBy(room => room.Building!.SortOrder)
+            .ThenBy(room => room.Code)
+            .Select(room => new
+            {
+                room.Id,
+                room.Code,
+                room.Name,
+                room.Capacity,
+                room.RoomType,
+                room.BuildingId,
+                BuildingName = room.Building!.Name,
+                CampusId = room.Building.CampusId,
+                CampusName = room.Building.Campus!.Name
+            })
+            .ToListAsync(cancellationToken);
+        return Ok(new { Items = items });
+    }
+
+    [HttpGet("mine")]
+    public async Task<ActionResult<PagedResult<ClassroomReservationDto>>> GetMine(
+        ClassroomReservationStatus? status,
+        [Range(1, int.MaxValue)] int page = 1,
+        [Range(1, 100)] int pageSize = 20,
+        CancellationToken cancellationToken = default)
+    {
+        var query = db.ClassroomReservations.AsNoTracking()
+            .Where(reservation =>
+                reservation.ApplicantUserId == scope.Current.UserId);
+        if (status.HasValue)
+            query = query.Where(reservation => reservation.Status == status.Value);
+        return Ok(await BuildPageAsync(query, page, pageSize, cancellationToken));
+    }
+
+    [HttpGet("review")]
+    [Authorize(Roles = SystemRoles.CollegeAdmin)]
+    public async Task<ActionResult<PagedResult<ClassroomReservationDto>>> GetReviewQueue(
+        ClassroomReservationStatus? status,
+        [Range(1, int.MaxValue)] int page = 1,
+        [Range(1, 100)] int pageSize = 20,
+        CancellationToken cancellationToken = default)
+    {
+        var collegeError = ReviewCollegeError();
+        if (collegeError is not null) return collegeError;
+        var collegeId = scope.Current.CollegeId!.Value;
+        var query = db.ClassroomReservations.AsNoTracking()
+            .Where(reservation => reservation.ApplicantCollegeId == collegeId);
+        if (status.HasValue)
+            query = query.Where(reservation => reservation.Status == status.Value);
+        else
+            query = query.Where(reservation =>
+                reservation.Status == ClassroomReservationStatus.Submitted);
+        return Ok(await BuildPageAsync(query, page, pageSize, cancellationToken));
+    }
+
+    [HttpPost]
+    public async Task<ActionResult> Create(
+        CreateClassroomReservationRequest request,
+        CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(request.Purpose))
+            return ValidationProblem("请填写借用用途。");
+        if (string.IsNullOrWhiteSpace(request.ContactPhone))
+            return ValidationProblem("请填写联系电话。");
+        var applicant = await ResolveApplicantAsync(cancellationToken);
+        if (applicant.Context is null)
+            return ConflictProblem(
+                applicant.Error ?? "当前账号未配置申请人学院，无法提交申请。");
+
+        var validation = await ValidateSlotAsync(
+            request.AcademicTermId,
+            request.ReservationDate,
+            request.StartPeriod,
+            request.PeriodCount,
+            cancellationToken);
+        if (validation.Error is not null) return validation.Error;
+
+        var classroom = await db.Classrooms.AsNoTracking()
+            .Where(room =>
+                room.Id == request.ClassroomId &&
+                room.IsEnabled &&
+                room.Building!.IsEnabled &&
+                room.Building.Campus!.IsEnabled)
+            .Select(room => new
+            {
+                room.Id,
+                room.Name,
+                room.Code,
+                room.Capacity,
+                BuildingName = room.Building!.Name
+            })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (classroom is null) return NotFound();
+        if (request.AttendeeCount > classroom.Capacity)
+            return ValidationProblem(
+                $"申请人数超过教室容量（{classroom.Capacity} 人）。");
+
+        var occupiedIds = await availabilityService.GetOccupiedClassroomIdsAsync(
+            validation.Term!,
+            request.ReservationDate,
+            request.StartPeriod,
+            request.PeriodCount,
+            null,
+            cancellationToken);
+        if (occupiedIds.Contains(classroom.Id))
+            return ConflictProblem("所选教室在该时段已有课程、考试或已批准预约。");
+
+        var duplicate = await db.ClassroomReservations.AsNoTracking()
+            .AnyAsync(reservation =>
+                reservation.ApplicantUserId == applicant.Context.User.Id &&
+                reservation.ClassroomId == classroom.Id &&
+                reservation.ReservationDate == request.ReservationDate &&
+                reservation.Status == ClassroomReservationStatus.Submitted &&
+                reservation.StartPeriod <
+                    request.StartPeriod + request.PeriodCount &&
+                request.StartPeriod <
+                    reservation.StartPeriod + reservation.PeriodCount,
+                cancellationToken);
+        if (duplicate)
+            return ConflictProblem("您已提交过同一教室、重叠时段的申请。");
+
+        var reservation = new ClassroomReservation
+        {
+            ApplicantUserId = applicant.Context.User.Id,
+            ApplicantName = applicant.Context.User.DisplayName,
+            ApplicantCollegeId = applicant.Context.CollegeId,
+            AcademicTermId = request.AcademicTermId,
+            ClassroomId = request.ClassroomId,
+            ReservationDate = request.ReservationDate,
+            StartPeriod = request.StartPeriod,
+            PeriodCount = request.PeriodCount,
+            AttendeeCount = request.AttendeeCount,
+            Purpose = request.Purpose.Trim(),
+            ContactPhone = request.ContactPhone.Trim(),
+            Notes = Normalize(request.Notes)
+        };
+        db.ClassroomReservations.Add(reservation);
+        await db.SaveChangesAsync(cancellationToken);
+        await NotificationService.SendToRoleAsync(
+            db,
+            SystemRoles.CollegeAdmin,
+            "教室借用申请待审核",
+            $"{reservation.ApplicantName} 申请于 {reservation.ReservationDate:yyyy-MM-dd} " +
+            $"借用 {classroom.BuildingName} {classroom.Name}。",
+            reservation.ApplicantCollegeId,
+            "/classroom-reservations",
+            cancellationToken,
+            NotificationCategory.Approval);
+        return Created("", new { reservation.Id });
+    }
+
+    [HttpPost("{id:guid}/cancel")]
+    public async Task<ActionResult> Cancel(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var reservation = await db.ClassroomReservations
+            .FirstOrDefaultAsync(item =>
+                item.Id == id &&
+                item.ApplicantUserId == scope.Current.UserId,
+                cancellationToken);
+        if (reservation is null) return NotFound();
+        if (reservation.Status is not (
+                ClassroomReservationStatus.Submitted or
+                ClassroomReservationStatus.Approved))
+            return ConflictProblem("当前状态不能取消。");
+        if (reservation.ReservationDate < TodayInChina())
+            return ConflictProblem("已过期的预约不能取消。");
+
+        var wasApproved =
+            reservation.Status == ClassroomReservationStatus.Approved;
+        reservation.Status = ClassroomReservationStatus.Cancelled;
+        reservation.CancelledAt = DateTime.UtcNow;
+        reservation.UpdatedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(cancellationToken);
+        if (wasApproved)
+        {
+            await NotificationService.SendToRoleAsync(
+                db,
+                SystemRoles.CollegeAdmin,
+                "已批准教室预约被申请人取消",
+                $"{reservation.ApplicantName} 已取消 " +
+                $"{reservation.ReservationDate:yyyy-MM-dd} 的教室预约。",
+                reservation.ApplicantCollegeId,
+                "/classroom-reservations",
+                cancellationToken,
+                NotificationCategory.Approval);
+        }
+        return NoContent();
+    }
+
+    [HttpPost("{id:guid}/approve")]
+    [Authorize(Roles = SystemRoles.CollegeAdmin)]
+    public Task<ActionResult> Approve(
+        Guid id,
+        ReviewClassroomReservationRequest request,
+        CancellationToken cancellationToken) =>
+        ReviewAsync(id, true, request.Comment, cancellationToken);
+
+    [HttpPost("{id:guid}/reject")]
+    [Authorize(Roles = SystemRoles.CollegeAdmin)]
+    public Task<ActionResult> Reject(
+        Guid id,
+        ReviewClassroomReservationRequest request,
+        CancellationToken cancellationToken)
+    {
+        if (string.IsNullOrWhiteSpace(request.Comment))
+            return Task.FromResult<ActionResult>(
+                ValidationProblem("驳回时必须填写审核意见。"));
+        return ReviewAsync(id, false, request.Comment, cancellationToken);
+    }
+
+    private async Task<ActionResult> ReviewAsync(
+        Guid id,
+        bool approve,
+        string? comment,
+        CancellationToken cancellationToken)
+    {
+        var collegeError = ReviewCollegeError();
+        if (collegeError is not null) return collegeError;
+        var reviewerCollegeId = scope.Current.CollegeId!.Value;
+
+        return await db.ExecuteInRetriableTransactionAsync<ActionResult>(
+            async transaction =>
+            {
+                db.ChangeTracker.Clear();
+                var reservation = await db.ClassroomReservations
+                    .Include(item => item.AcademicTerm)
+                    .Include(item => item.Classroom)
+                    .FirstOrDefaultAsync(item => item.Id == id, cancellationToken);
+                if (reservation is null) return NotFound();
+                if (reservation.ApplicantCollegeId != reviewerCollegeId)
+                    return Forbid();
+                if (reservation.Status != ClassroomReservationStatus.Submitted)
+                    return ConflictProblem("该申请已处理，不能重复审核。");
+
+                if (approve)
+                {
+                    if (reservation.ReservationDate < TodayInChina())
+                        return ConflictProblem("预约日期已过，不能批准。");
+                    var validation = await ValidateSlotAsync(
+                        reservation.AcademicTermId,
+                        reservation.ReservationDate,
+                        reservation.StartPeriod,
+                        reservation.PeriodCount,
+                        cancellationToken);
+                    if (validation.Error is not null) return validation.Error;
+                    if (reservation.AttendeeCount > reservation.Classroom!.Capacity)
+                        return ConflictProblem("申请人数已超过教室当前容量，不能批准。");
+                    var occupiedIds =
+                        await availabilityService.GetOccupiedClassroomIdsAsync(
+                            validation.Term!,
+                            reservation.ReservationDate,
+                            reservation.StartPeriod,
+                            reservation.PeriodCount,
+                            reservation.Id,
+                            cancellationToken);
+                    if (occupiedIds.Contains(reservation.ClassroomId))
+                        return ConflictProblem(
+                            "教室在该时段已被课程、考试或其他已批准预约占用。");
+                    reservation.Status = ClassroomReservationStatus.Approved;
+                }
+                else
+                {
+                    reservation.Status = ClassroomReservationStatus.Rejected;
+                }
+
+                reservation.ReviewedByUserId = scope.Current.UserId;
+                reservation.ReviewedAt = DateTime.UtcNow;
+                reservation.ReviewComment = Normalize(comment);
+                reservation.UpdatedAt = DateTime.UtcNow;
+                await NotificationService.SendAsync(
+                    db,
+                    reservation.ApplicantUserId,
+                    approve ? "教室借用申请已通过" : "教室借用申请已驳回",
+                    approve
+                        ? $"{reservation.ReservationDate:yyyy-MM-dd} 的教室借用申请已通过。"
+                        : reservation.ReviewComment ?? "审核未通过。",
+                    "/classroom-reservations",
+                    cancellationToken,
+                    NotificationCategory.Approval);
+                await transaction.CommitAsync(cancellationToken);
+                return NoContent();
+            },
+            cancellationToken,
+            IsolationLevel.Serializable);
+    }
+
+    private async Task<PagedResult<ClassroomReservationDto>> BuildPageAsync(
+        IQueryable<ClassroomReservation> query,
+        int page,
+        int pageSize,
+        CancellationToken cancellationToken)
+    {
+        var total = await query.CountAsync(cancellationToken);
+        var items = await query
+            .OrderByDescending(reservation =>
+                reservation.Status == ClassroomReservationStatus.Submitted)
+            .ThenByDescending(reservation => reservation.CreatedAt)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .Select(reservation => new ClassroomReservationDto(
+                reservation.Id,
+                reservation.ApplicantUserId,
+                reservation.ApplicantName,
+                reservation.ApplicantCollegeId,
+                reservation.ApplicantCollege!.Name,
+                reservation.AcademicTermId,
+                reservation.AcademicTerm!.Name,
+                reservation.ClassroomId,
+                reservation.Classroom!.Code,
+                reservation.Classroom.Name,
+                reservation.Classroom.Building!.Name,
+                reservation.Classroom.Building.Campus!.Name,
+                reservation.ReservationDate,
+                reservation.StartPeriod,
+                reservation.PeriodCount,
+                reservation.AttendeeCount,
+                reservation.Purpose,
+                reservation.ContactPhone,
+                reservation.Notes,
+                reservation.Status,
+                reservation.ReviewComment,
+                reservation.ReviewedAt,
+                reservation.CancelledAt,
+                reservation.CreatedAt))
+            .ToListAsync(cancellationToken);
+        return new PagedResult<ClassroomReservationDto>(
+            items,
+            total,
+            page,
+            pageSize);
+    }
+
+    private async Task<(
+        AcademicTerm? Term,
+        ActionResult? Error)> ValidateSlotAsync(
+        Guid academicTermId,
+        DateOnly reservationDate,
+        int startPeriod,
+        int periodCount,
+        CancellationToken cancellationToken)
+    {
+        var term = await db.AcademicTerms.AsNoTracking()
+            .FirstOrDefaultAsync(item =>
+                item.Id == academicTermId &&
+                item.IsEnabled &&
+                !item.IsArchived,
+                cancellationToken);
+        if (term is null) return (null, NotFound());
+        if (reservationDate < TodayInChina())
+            return (null, ValidationProblem("预约日期不能早于今天。"));
+        if (reservationDate < term.StartDate || reservationDate > term.EndDate)
+            return (null, ValidationProblem("预约日期不在所选学期范围内。"));
+        var hasPublishedTimetable = await db.SchedulePlans.AsNoTracking()
+            .AnyAsync(plan =>
+                plan.AcademicTermId == term.Id &&
+                plan.Status == SchedulePlanStatus.Published,
+                cancellationToken);
+        if (!hasPublishedTimetable)
+            return (null, ConflictProblem(
+                "所选学期的正式课表尚未发布，暂不能提交教室预约。"));
+
+        var requestedPeriods = Enumerable.Range(startPeriod, periodCount).ToArray();
+        var configuredPeriodCount = await db.ScheduleTimeSlots.AsNoTracking()
+            .CountAsync(slot =>
+                slot.AcademicTermId == academicTermId,
+                cancellationToken);
+        if (configuredPeriodCount == 0)
+        {
+            if (requestedPeriods.Any(period => period > 12))
+                return (null, ValidationProblem("预约范围包含不存在的节次。"));
+        }
+        else
+        {
+            var enabledPeriods = await db.ScheduleTimeSlots.AsNoTracking()
+                .Where(slot =>
+                    slot.AcademicTermId == academicTermId &&
+                    slot.IsEnabled)
+                .WhereIn(requestedPeriods, slot => slot.PeriodNumber)
+                .CountAsync(cancellationToken);
+            if (enabledPeriods != requestedPeriods.Length)
+                return (null, ValidationProblem("预约范围包含不存在或未启用的节次。"));
+        }
+        return (term, null);
+    }
+
+    private async Task<List<ClassroomReservationTimeSlotDto>> LoadTimeSlotsAsync(
+        Guid? academicTermId,
+        CancellationToken cancellationToken)
+    {
+        var result = academicTermId.HasValue
+            ? await db.ScheduleTimeSlots.AsNoTracking()
+                .Where(slot =>
+                    slot.AcademicTermId == academicTermId.Value &&
+                    slot.IsEnabled)
+                .OrderBy(slot => slot.PeriodNumber)
+                .Select(slot => new ClassroomReservationTimeSlotDto(
+                    slot.PeriodNumber,
+                    slot.Name,
+                    slot.StartsAt.ToString("HH:mm"),
+                    slot.EndsAt.ToString("HH:mm")))
+                .ToListAsync(cancellationToken)
+            : [];
+        return result.Count > 0
+            ? result
+            : Enumerable.Range(1, 12)
+                .Select(period => new ClassroomReservationTimeSlotDto(
+                    period,
+                    $"第 {period} 节",
+                    "",
+                    ""))
+                .ToList();
+    }
+
+    private async Task<ApplicantResolution> ResolveApplicantAsync(
+        CancellationToken cancellationToken)
+    {
+        if (scope.Current.UserId == Guid.Empty)
+            return new(null, "无法识别当前登录账号。");
+        var user = await db.Users.AsNoTracking()
+            .FirstOrDefaultAsync(item =>
+                item.Id == scope.Current.UserId &&
+                item.IsEnabled,
+                cancellationToken);
+        if (user is null) return new(null, "当前账号不存在或已停用。");
+
+        var linkedCollegeIds = new List<Guid>();
+        if (user.CollegeId.HasValue) linkedCollegeIds.Add(user.CollegeId.Value);
+        var teacherCollegeId = await db.Teachers.AsNoTracking()
+            .Where(teacher => teacher.UserId == user.Id)
+            .Select(teacher => (Guid?)teacher.CollegeId)
+            .FirstOrDefaultAsync(cancellationToken);
+        if (teacherCollegeId.HasValue)
+            linkedCollegeIds.Add(teacherCollegeId.Value);
+        var studentCollegeId = await db.Students.AsNoTracking()
+            .Where(student => student.UserId == user.Id)
+            .Select(student =>
+                (Guid?)student.AdministrativeClass!.Major!.CollegeId)
+            .FirstOrDefaultAsync(cancellationToken);
+        if (studentCollegeId.HasValue)
+            linkedCollegeIds.Add(studentCollegeId.Value);
+
+        var distinctIds = linkedCollegeIds.Distinct().ToArray();
+        if (distinctIds.Length == 0)
+            return new(null, "当前账号未配置所在学院，请联系账号管理员补充学院信息。");
+        if (distinctIds.Length > 1)
+            return new(null, "账号与人员档案的学院信息不一致，请联系管理员修正后再申请。");
+        var college = await db.Colleges.AsNoTracking()
+            .Where(item => item.Id == distinctIds[0] && item.IsEnabled)
+            .Select(item => new { item.Id, item.Name })
+            .FirstOrDefaultAsync(cancellationToken);
+        return college is null
+            ? new(null, "当前账号所属学院不存在或已停用。")
+            : new(
+                new ApplicantContext(user, college.Id, college.Name),
+                null);
+    }
+
+    private ActionResult? ReviewCollegeError()
+    {
+        if (!scope.Current.IsInRole(SystemRoles.CollegeAdmin))
+            return Forbid();
+        return scope.Current.CollegeId.HasValue
+            ? null
+            : ConflictProblem("学院管理员账号未配置所属学院，无法审核。");
+    }
+
+    private ActionResult ConflictProblem(string detail) =>
+        Conflict(new ProblemDetails
+        {
+            Title = "无法完成教室预约",
+            Detail = detail,
+            Status = StatusCodes.Status409Conflict
+        });
+
+    private static string? Normalize(string? value) =>
+        string.IsNullOrWhiteSpace(value) ? null : value.Trim();
+
+    private static DateOnly TodayInChina()
+    {
+        foreach (var id in new[] { "Asia/Shanghai", "China Standard Time" })
+        {
+            try
+            {
+                var zone = TimeZoneInfo.FindSystemTimeZoneById(id);
+                return DateOnly.FromDateTime(
+                    TimeZoneInfo.ConvertTime(DateTimeOffset.UtcNow, zone).DateTime);
+            }
+            catch (TimeZoneNotFoundException)
+            {
+            }
+            catch (InvalidTimeZoneException)
+            {
+            }
+        }
+        return DateOnly.FromDateTime(DateTime.Today);
+    }
+
+    private sealed record ApplicantContext(
+        ApplicationUser User,
+        Guid CollegeId,
+        string CollegeName);
+
+    private sealed record ApplicantResolution(
+        ApplicantContext? Context,
+        string? Error);
+}
+
+public sealed record CreateClassroomReservationRequest(
+    Guid AcademicTermId,
+    Guid ClassroomId,
+    DateOnly ReservationDate,
+    [Range(1, 30)] int StartPeriod,
+    [Range(1, 6)] int PeriodCount,
+    [Range(1, 10000)] int AttendeeCount,
+    [Required, StringLength(200)] string Purpose,
+    [Required, StringLength(30)] string ContactPhone,
+    [StringLength(500)] string? Notes);
+
+public sealed record ReviewClassroomReservationRequest(
+    [StringLength(500)] string? Comment);
+
+public sealed record ClassroomReservationTimeSlotDto(
+    int PeriodNumber,
+    string Name,
+    string StartTime,
+    string EndTime);
+
+public sealed record ClassroomReservationDto(
+    Guid Id,
+    Guid ApplicantUserId,
+    string ApplicantName,
+    Guid ApplicantCollegeId,
+    string ApplicantCollegeName,
+    Guid AcademicTermId,
+    string AcademicTermName,
+    Guid ClassroomId,
+    string ClassroomCode,
+    string ClassroomName,
+    string BuildingName,
+    string CampusName,
+    DateOnly ReservationDate,
+    int StartPeriod,
+    int PeriodCount,
+    int AttendeeCount,
+    string Purpose,
+    string ContactPhone,
+    string? Notes,
+    ClassroomReservationStatus Status,
+    string? ReviewComment,
+    DateTime? ReviewedAt,
+    DateTime? CancelledAt,
+    DateTime CreatedAt);

src/Jiaowu.Api/Controllers/CourseAdjustmentsController.cs

@@ -3,6 +3,8 @@ using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
 using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Scheduling;
+using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -27,6 +29,145 @@ public sealed class CourseAdjustmentsController(
         SystemRoles.AcademicAdmin + "," +
         SystemRoles.CollegeAdmin;
 
+    [HttpGet("task-options")]
+    [Authorize(Roles = Applicants)]
+    public async Task<ActionResult> GetTaskOptions(
+        Guid? academicTermId,
+        CancellationToken cancellationToken)
+    {
+        var source = AccessibleTeachingTasks().AsNoTracking()
+            .Where(x => x.Status == TeachingTaskStatus.Published);
+        if (academicTermId.HasValue)
+            source = source.Where(x => x.AcademicTermId == academicTermId);
+
+        return Ok(await source
+            .OrderByDescending(x => x.AcademicTerm!.StartDate)
+            .ThenBy(x => x.Course!.Code)
+            .ThenBy(x => x.TaskNumber)
+            .Select(x => new
+            {
+                x.Id,
+                x.TaskNumber,
+                x.Name,
+                x.AcademicTermId,
+                TermName = x.AcademicTerm!.Name,
+                CourseCode = x.Course!.Code,
+                CourseName = x.Course.Name,
+                ClassNames = x.Classes
+                    .OrderBy(item => item.AdministrativeClass!.Code)
+                    .Select(item => item.AdministrativeClass!.Name)
+            })
+            .ToListAsync(cancellationToken));
+    }
+
+    [HttpGet("tasks/{teachingTaskId:guid}/session-options")]
+    [Authorize(Roles = Applicants)]
+    public async Task<ActionResult> GetSessionOptions(
+        Guid teachingTaskId,
+        CancellationToken cancellationToken)
+    {
+        var task = await AccessibleTeachingTasks().AsNoTracking()
+            .Where(x =>
+                x.Id == teachingTaskId &&
+                x.Status == TeachingTaskStatus.Published)
+            .Select(x => new
+            {
+                x.Id,
+                x.TaskNumber,
+                CourseName = x.Course!.Name,
+                x.AcademicTermId,
+                TermStartDate = x.AcademicTerm!.StartDate,
+                TermEndDate = x.AcademicTerm.EndDate
+            })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (task is null) return NotFound();
+
+        var entries = await db.ScheduleEntries.AsNoTracking()
+            .Where(x =>
+                x.TeachingTaskId == teachingTaskId &&
+                x.SchedulePlan!.Status == SchedulePlanStatus.Published)
+            .OrderBy(x => x.DayOfWeek)
+            .ThenBy(x => x.StartPeriod)
+            .Select(x => new
+            {
+                x.Id,
+                x.DayOfWeek,
+                x.StartPeriod,
+                x.PeriodCount,
+                x.StartWeek,
+                x.EndWeek,
+                x.WeekPattern,
+                x.ClassroomId,
+                ClassroomName = x.Classroom != null ? x.Classroom.Name : null,
+                BuildingName = x.Classroom != null ? x.Classroom.Building!.Name : null
+            })
+            .ToListAsync(cancellationToken);
+
+        var occupied = await db.CourseAdjustments.AsNoTracking()
+            .Where(x =>
+                x.TeachingTaskId == teachingTaskId &&
+                x.SourceScheduleEntryId != null &&
+                x.SourceWeek != null &&
+                (x.Status == CourseAdjustmentStatus.Submitted ||
+                 x.Status == CourseAdjustmentStatus.Approved))
+            .Select(x => new { x.SourceScheduleEntryId, x.SourceWeek })
+            .ToListAsync(cancellationToken);
+        var occupiedOccurrences = occupied
+            .Select(x => (x.SourceScheduleEntryId!.Value, x.SourceWeek!.Value))
+            .ToHashSet();
+
+        var sessions = entries
+            .SelectMany(entry => Enumerable.Range(
+                    entry.StartWeek,
+                    entry.EndWeek - entry.StartWeek + 1)
+                .Where(week => IncludesWeek(entry.WeekPattern, week))
+                .Select(week => new
+                {
+                    ScheduleEntryId = entry.Id,
+                    Week = week,
+                    Date = ResolveDate(task.TermStartDate, week, entry.DayOfWeek),
+                    entry.DayOfWeek,
+                    entry.StartPeriod,
+                    entry.PeriodCount,
+                    entry.ClassroomId,
+                    entry.ClassroomName,
+                    entry.BuildingName,
+                    HasExistingAdjustment = occupiedOccurrences.Contains((entry.Id, week))
+                }))
+            .Where(x => x.Date >= task.TermStartDate && x.Date <= task.TermEndDate)
+            .OrderBy(x => x.Date)
+            .ThenBy(x => x.StartPeriod)
+            .ToList();
+
+        var classrooms = await db.Classrooms.AsNoTracking()
+            .Where(x => x.IsEnabled)
+            .OrderBy(x => x.Building!.Campus!.SortOrder)
+            .ThenBy(x => x.Building!.SortOrder)
+            .ThenBy(x => x.SortOrder)
+            .Select(x => new
+            {
+                x.Id,
+                x.Name,
+                BuildingName = x.Building!.Name,
+                CampusName = x.Building.Campus!.Name,
+                x.Capacity
+            })
+            .ToListAsync(cancellationToken);
+        var periods = await db.ScheduleTimeSlots.AsNoTracking()
+            .Where(x => x.AcademicTermId == task.AcademicTermId && x.IsEnabled)
+            .OrderBy(x => x.PeriodNumber)
+            .Select(x => new
+            {
+                x.PeriodNumber,
+                x.Name,
+                StartsAt = x.StartsAt.ToString("HH:mm"),
+                EndsAt = x.EndsAt.ToString("HH:mm")
+            })
+            .ToListAsync(cancellationToken);
+
+        return Ok(new { Task = task, Sessions = sessions, Classrooms = classrooms, Periods = periods });
+    }
+
     // ═══════════════ My adjustments ═══════════════
 
     [HttpGet("mine")]
@@ -100,20 +241,41 @@ public sealed class CourseAdjustmentsController(
         var validation = await ValidateRequestAsync(request, cancellationToken);
         if (validation is not null) return validation;
 
+        var source = RequiresSourceOccurrence(request.Type)
+            ? await LoadSourceOccurrenceAsync(
+                request.TeachingTaskId,
+                request.SourceScheduleEntryId,
+                request.SourceWeek,
+                cancellationToken)
+            : null;
+        var targetDayOfWeek = request.TargetDate.HasValue
+            ? ToIsoDayOfWeek(request.TargetDate.Value.DayOfWeek)
+            : request.DayOfWeek;
+
         var adj = new CourseAdjustment
         {
             TeachingTaskId = request.TeachingTaskId,
             Type = request.Type,
             ApplicantUserId = userId,
             Reason = request.Reason.Trim(),
+            SourceScheduleEntryId = source?.Entry.Id,
+            SourceWeek = source?.Week,
+            SourceDate = source?.Date,
+            SourceStartPeriod = source?.Entry.StartPeriod,
+            SourcePeriodCount = source?.Entry.PeriodCount,
+            SourceClassroomId = source?.Entry.ClassroomId,
             TargetDate = request.TargetDate,
-            DayOfWeek = request.DayOfWeek,
+            DayOfWeek = targetDayOfWeek,
             StartPeriod = request.StartPeriod,
-            PeriodCount = request.PeriodCount,
+            PeriodCount = source?.Entry.PeriodCount ?? request.PeriodCount,
             ClassroomId = request.ClassroomId,
             SubstituteTeacherId = request.SubstituteTeacherId,
-            CancelWeek = request.CancelWeek,
+            CancelWeek = request.Type == CourseAdjustmentType.Cancel
-            CancelDate = request.CancelDate
+                ? source?.Week
+                : request.CancelWeek,
+            CancelDate = request.Type == CourseAdjustmentType.Cancel
+                ? source?.Date
+                : request.CancelDate
         };
 
         if (request.Submit)
@@ -138,7 +300,8 @@ public sealed class CourseAdjustmentsController(
                     SystemRoles.CollegeAdmin,
                     $"新的{tl}申请",
                     $"《{taskInfo.Name}》提交了{tl}申请，请及时审核。",
-                    taskInfo.CollegeId, "/course-adjustments", cancellationToken);
+                    taskInfo.CollegeId, "/course-adjustments", cancellationToken,
+                    NotificationCategory.Schedule);
             }
         }
 
@@ -161,6 +324,25 @@ public sealed class CourseAdjustmentsController(
         if (adj.Status != CourseAdjustmentStatus.Draft)
             return ConflictProblem("只有草稿可以提交。");
 
+        var validation = await ValidateRequestAsync(
+            new CourseAdjustmentRequest(
+                adj.TeachingTaskId,
+                adj.Type,
+                adj.Reason,
+                true,
+                adj.TargetDate,
+                adj.DayOfWeek,
+                adj.StartPeriod,
+                adj.PeriodCount,
+                adj.ClassroomId,
+                adj.SubstituteTeacherId,
+                adj.CancelWeek,
+                adj.CancelDate,
+                adj.SourceScheduleEntryId,
+                adj.SourceWeek),
+            cancellationToken);
+        if (validation is not null) return validation;
+
         adj.Status = CourseAdjustmentStatus.Submitted;
         adj.SubmittedAt = DateTime.UtcNow;
         await db.SaveChangesAsync(cancellationToken);
@@ -171,12 +353,14 @@ public sealed class CourseAdjustmentsController(
             $"新的{TypeLabel(adj.Type)}申请",
             $"《{courseName}》提交了{TypeLabel(adj.Type)}申请，请及时审核。",
             adj.TeachingTask.Course.CollegeId,
-            "/course-adjustments", cancellationToken);
+            "/course-adjustments", cancellationToken,
+            NotificationCategory.Schedule);
         await NotificationService.SendToRoleAsync(db,
             SystemRoles.AcademicAdmin,
             $"新的{TypeLabel(adj.Type)}申请",
             $"《{courseName}》提交了{TypeLabel(adj.Type)}申请。",
-            null, "/course-adjustments", cancellationToken);
+            null, "/course-adjustments", cancellationToken,
+            NotificationCategory.Schedule);
         return NoContent();
     }
 
@@ -190,6 +374,12 @@ public sealed class CourseAdjustmentsController(
             .Include(x => x.TeachingTask)
             .ThenInclude(x => x!.Course)
             .ThenInclude(x => x!.College)
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Classes)
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.AcademicTerm)
             .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
         if (adj is null) return NotFound();
 
@@ -200,6 +390,12 @@ public sealed class CourseAdjustmentsController(
         if (adj.Status != CourseAdjustmentStatus.Submitted)
             return ConflictProblem("只有待审核的申请可以审批。");
 
+        var scheduleProblem = await ValidateApprovalScheduleAsync(
+            adj,
+            cancellationToken);
+        if (scheduleProblem is not null)
+            return ConflictProblem(scheduleProblem);
+
         adj.Status = CourseAdjustmentStatus.Approved;
         adj.ReviewedAt = DateTime.UtcNow;
         adj.ReviewedByUserId = currentUserDataScope.Current.UserId;
@@ -213,14 +409,13 @@ public sealed class CourseAdjustmentsController(
         await NotificationService.SendAsync(db, adj.ApplicantUserId,
             "调停课申请已通过",
             $"您的{TypeLabel(adj.Type)}申请（{adj.TeachingTask!.Course!.Name}）已通过审核。",
-            "/course-adjustments", cancellationToken);
+            "/course-adjustments", cancellationToken,
+            NotificationCategory.Schedule);
 
         // Notify affected students
-        var studentUserIds = await db.CourseEnrollments
+        var studentUserIds = await TeachingTaskRosterQuery
-            .Where(x =>
+            .ForTask(db, adj.TeachingTaskId)
-                x.CourseSelectionOffering!.TeachingTaskId == adj.TeachingTaskId &&
+            .Select(x => x.UserId)
-                x.Status == CourseEnrollmentStatus.Enrolled)
-            .Select(x => x.Student!.UserId)
             .Where(uid => uid != null)
             .Select(uid => uid!.Value)
             .Distinct()
@@ -230,7 +425,8 @@ public sealed class CourseAdjustmentsController(
             await NotificationService.SendToUserIdsAsync(db, studentUserIds,
                 "课程变动通知",
                 $"《{adj.TeachingTask.Course.Name}》有{TypeLabel(adj.Type)}变动，请查看课表。",
-                "/my-timetable", cancellationToken);
+                "/my-timetable", cancellationToken,
+                NotificationCategory.Schedule);
         }
 
         return NoContent();
@@ -242,81 +438,19 @@ public sealed class CourseAdjustmentsController(
         switch (adj.Type)
         {
             case CourseAdjustmentType.Reschedule:
-                // Update existing schedule entries for this teaching task
+                var rescheduleSource = await LoadSourceEntryAsync(adj, ct);
-                if (adj.DayOfWeek.HasValue && adj.StartPeriod.HasValue)
+                ExcludeWeek(rescheduleSource, adj.SourceWeek!.Value);
-                {
+                db.ScheduleEntries.Add(CreateTargetEntry(adj, rescheduleSource.SchedulePlanId));
-                    var entries = await db.ScheduleEntries
-                        .Where(x => x.TeachingTaskId == adj.TeachingTaskId)
-                        .ToListAsync(ct);
-                    foreach (var entry in entries)
-                    {
-                        entry.DayOfWeek = adj.DayOfWeek.Value;
-                        entry.StartPeriod = adj.StartPeriod.Value;
-                        entry.PeriodCount = adj.PeriodCount ?? entry.PeriodCount;
-                    }
-                    if (adj.ClassroomId.HasValue)
-                    {
-                        foreach (var entry in entries)
-                            entry.ClassroomId = adj.ClassroomId.Value;
-                    }
-                }
                 break;
 
             case CourseAdjustmentType.Cancel:
-                // Cancel: remove schedule entries for the specified week
+                var cancelSource = await LoadSourceEntryAsync(adj, ct);
-                if (adj.CancelWeek.HasValue)
+                ExcludeWeek(cancelSource, adj.SourceWeek!.Value);
-                {
-                    var entries = await db.ScheduleEntries
-                        .Where(x => x.TeachingTaskId == adj.TeachingTaskId &&
-                                    x.StartWeek <= adj.CancelWeek.Value &&
-                                    x.EndWeek >= adj.CancelWeek.Value)
-                        .ToListAsync(ct);
-                    foreach (var entry in entries)
-                    {
-                        // Split the entry to exclude the cancelled week
-                        if (entry.StartWeek == adj.CancelWeek.Value &&
-                            entry.EndWeek == adj.CancelWeek.Value)
-                        {
-                            db.ScheduleEntries.Remove(entry);
-                        }
-                        else if (entry.StartWeek == adj.CancelWeek.Value)
-                        {
-                            entry.StartWeek = adj.CancelWeek.Value + 1;
-                        }
-                        else if (entry.EndWeek == adj.CancelWeek.Value)
-                        {
-                            entry.EndWeek = adj.CancelWeek.Value - 1;
-                        }
-                    }
-                }
                 break;
 
             case CourseAdjustmentType.Makeup:
-                // Makeup: add a temp schedule entry for the makeup date
+                var makeupSource = await LoadSourceEntryAsync(adj, ct);
-                if (adj.TargetDate.HasValue && adj.DayOfWeek.HasValue &&
+                db.ScheduleEntries.Add(CreateTargetEntry(adj, makeupSource.SchedulePlanId));
-                    adj.StartPeriod.HasValue)
-                {
-                    var publishedPlan = await db.SchedulePlans
-                        .Where(x => x.AcademicTermId == adj.TeachingTask!.AcademicTermId &&
-                                    x.Status == SchedulePlanStatus.Published)
-                        .FirstOrDefaultAsync(ct);
-                    if (publishedPlan is not null)
-                    {
-                        db.ScheduleEntries.Add(new ScheduleEntry
-                        {
-                            SchedulePlanId = publishedPlan.Id,
-                            TeachingTaskId = adj.TeachingTaskId,
-                            ClassroomId = adj.ClassroomId,
-                            DayOfWeek = adj.DayOfWeek.Value,
-                            StartPeriod = adj.StartPeriod.Value,
-                            PeriodCount = adj.PeriodCount ?? 2,
-                            StartWeek = 1,
-                            EndWeek = 1,
-                            WeekPattern = WeekPattern.All,
-                            Notes = $"补课（原申请 {adj.CreatedAt:yyyy-MM-dd}）"
-                        });
-                    }
-                }
                 break;
 
             case CourseAdjustmentType.Substitute:
@@ -383,7 +517,8 @@ public sealed class CourseAdjustmentsController(
             : $"您的{TypeLabel(adj.Type)}申请已退回。";
         await NotificationService.SendAsync(db, adj.ApplicantUserId,
             $"{TypeLabel(adj.Type)}申请已退回", msg,
-            "/course-adjustments", cancellationToken);
+            "/course-adjustments", cancellationToken,
+            NotificationCategory.Schedule);
         return NoContent();
     }
 
@@ -393,7 +528,7 @@ public sealed class CourseAdjustmentsController(
         CourseAdjustmentRequest request,
         CancellationToken cancellationToken)
     {
-        var task = await db.TeachingTasks.AsNoTracking()
+        var task = await AccessibleTeachingTasks().AsNoTracking()
             .Include(x => x.Course)
             .FirstOrDefaultAsync(x =>
                 x.Id == request.TeachingTaskId &&
@@ -405,15 +540,13 @@ public sealed class CourseAdjustmentsController(
         {
             case CourseAdjustmentType.Reschedule:
             case CourseAdjustmentType.Makeup:
-                if (!request.DayOfWeek.HasValue || request.DayOfWeek is < 1 or > 7)
+                if (!request.TargetDate.HasValue)
-                    return ValidationProblem("请选择有效的上课日。");
+                    return ValidationProblem(
+                        request.Type == CourseAdjustmentType.Reschedule
+                            ? "请选择调课后的日期。"
+                            : "请选择补课日期。");
                 if (!request.StartPeriod.HasValue || request.StartPeriod < 1)
                     return ValidationProblem("请选择起始节次。");
-                if (!request.PeriodCount.HasValue || request.PeriodCount < 1)
-                    return ValidationProblem("请选择持续节数。");
-                if (request.Type == CourseAdjustmentType.Makeup &&
-                    !request.TargetDate.HasValue)
-                    return ValidationProblem("补课必须指定日期。");
                 break;
             case CourseAdjustmentType.Substitute:
                 if (!request.SubstituteTeacherId.HasValue)
@@ -424,15 +557,241 @@ public sealed class CourseAdjustmentsController(
                     return ValidationProblem("代课教师不存在或已离职。");
                 break;
             case CourseAdjustmentType.Cancel:
-                if (!request.CancelWeek.HasValue && !request.CancelDate.HasValue)
-                    return ValidationProblem("停课需指定周次或日期。");
                 break;
         }
 
+        if (RequiresSourceOccurrence(request.Type))
+        {
+            var source = await LoadSourceOccurrenceAsync(
+                request.TeachingTaskId,
+                request.SourceScheduleEntryId,
+                request.SourceWeek,
+                cancellationToken);
+            if (source is null)
+                return ValidationProblem("请选择当前已发布课表中的具体原课次。");
+
+            var duplicate = await db.CourseAdjustments.AsNoTracking().AnyAsync(x =>
+                x.SourceScheduleEntryId == source.Entry.Id &&
+                x.SourceWeek == source.Week &&
+                (x.Status == CourseAdjustmentStatus.Submitted ||
+                 x.Status == CourseAdjustmentStatus.Approved),
+                cancellationToken);
+            if (duplicate)
+                return ConflictProblem("该课次已有待审核或已通过的调停课记录。");
+
+            if (request.TargetDate.HasValue &&
+                (request.TargetDate < source.Term.StartDate ||
+                 request.TargetDate > source.Term.EndDate))
+                return ValidationProblem("目标日期必须在本学期起止日期内。");
+        }
+
+        if (request.ClassroomId.HasValue &&
+            !await db.Classrooms.AsNoTracking().AnyAsync(x =>
+                x.Id == request.ClassroomId && x.IsEnabled,
+                cancellationToken))
+            return ValidationProblem("目标教室不存在或已停用。");
+
+        return null;
+    }
+
+    private async Task<string?> ValidateApprovalScheduleAsync(
+        CourseAdjustment adjustment,
+        CancellationToken cancellationToken)
+    {
+        if (!RequiresSourceOccurrence(adjustment.Type)) return null;
+
+        var source = await LoadSourceOccurrenceAsync(
+            adjustment.TeachingTaskId,
+            adjustment.SourceScheduleEntryId,
+            adjustment.SourceWeek,
+            cancellationToken);
+        if (source is null)
+            return "原课次已不在当前发布课表中，请退回后重新选择。";
+        if (adjustment.Type == CourseAdjustmentType.Cancel) return null;
+        if (!adjustment.TargetDate.HasValue || !adjustment.StartPeriod.HasValue)
+            return "目标上课日期或节次不完整。";
+
+        var targetWeek = ResolveWeek(source.Term.StartDate, adjustment.TargetDate.Value);
+        var targetDay = ToIsoDayOfWeek(adjustment.TargetDate.Value.DayOfWeek);
+        var target = new ScheduleEntry
+        {
+            TeachingTaskId = adjustment.TeachingTaskId,
+            TeachingTask = adjustment.TeachingTask,
+            ClassroomId = adjustment.ClassroomId ?? adjustment.SourceClassroomId,
+            DayOfWeek = targetDay,
+            StartPeriod = adjustment.StartPeriod.Value,
+            PeriodCount = adjustment.SourcePeriodCount ?? source.Entry.PeriodCount,
+            StartWeek = targetWeek,
+            EndWeek = targetWeek,
+            WeekPattern = WeekPattern.All
+        };
+        var possibleConflicts = await db.ScheduleEntries.AsNoTracking()
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Classes)
+            .Where(x =>
+                x.SchedulePlan!.Status == SchedulePlanStatus.Published &&
+                x.Id != adjustment.SourceScheduleEntryId &&
+                x.DayOfWeek == targetDay &&
+                x.StartWeek <= targetWeek &&
+                x.EndWeek >= targetWeek &&
+                x.StartPeriod < target.StartPeriod + target.PeriodCount &&
+                target.StartPeriod < x.StartPeriod + x.PeriodCount)
+            .ToListAsync(cancellationToken);
+        foreach (var existing in possibleConflicts.Where(x =>
+                     IncludesWeek(x.WeekPattern, targetWeek)))
+        {
+            var reason = ScheduleConflictDetector.ConflictReason(target, existing);
+            if (reason is not null)
+                return $"目标时间存在{reason}冲突：{existing.TeachingTask!.Name}。";
+        }
+
         return null;
     }
 
-    private static System.Linq.Expressions.Expression<
+    private async Task<SourceOccurrence?> LoadSourceOccurrenceAsync(
+        Guid teachingTaskId,
+        Guid? scheduleEntryId,
+        int? week,
+        CancellationToken cancellationToken)
+    {
+        if (!scheduleEntryId.HasValue || !week.HasValue) return null;
+        var entry = await db.ScheduleEntries.AsNoTracking()
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.AcademicTerm)
+            .FirstOrDefaultAsync(x =>
+                x.Id == scheduleEntryId.Value &&
+                x.TeachingTaskId == teachingTaskId &&
+                x.SchedulePlan!.Status == SchedulePlanStatus.Published,
+                cancellationToken);
+        if (entry?.TeachingTask?.AcademicTerm is null ||
+            week < entry.StartWeek || week > entry.EndWeek ||
+            !IncludesWeek(entry.WeekPattern, week.Value))
+            return null;
+        var date = ResolveDate(
+            entry.TeachingTask.AcademicTerm.StartDate,
+            week.Value,
+            entry.DayOfWeek);
+        if (date < entry.TeachingTask.AcademicTerm.StartDate ||
+            date > entry.TeachingTask.AcademicTerm.EndDate)
+            return null;
+        return new SourceOccurrence(
+            entry,
+            entry.TeachingTask.AcademicTerm,
+            week.Value,
+            date);
+    }
+
+    private Task<ScheduleEntry> LoadSourceEntryAsync(
+        CourseAdjustment adjustment,
+        CancellationToken cancellationToken) =>
+        db.ScheduleEntries.SingleAsync(x =>
+            x.Id == adjustment.SourceScheduleEntryId &&
+            x.TeachingTaskId == adjustment.TeachingTaskId &&
+            x.SchedulePlan!.Status == SchedulePlanStatus.Published,
+            cancellationToken);
+
+    private void ExcludeWeek(ScheduleEntry entry, int week)
+    {
+        db.ScheduleEntries.Remove(entry);
+        if (entry.StartWeek <= week - 1 &&
+            HasIncludedWeek(entry.WeekPattern, entry.StartWeek, week - 1))
+            db.ScheduleEntries.Add(CloneEntry(entry, entry.StartWeek, week - 1));
+        if (week + 1 <= entry.EndWeek &&
+            HasIncludedWeek(entry.WeekPattern, week + 1, entry.EndWeek))
+            db.ScheduleEntries.Add(CloneEntry(entry, week + 1, entry.EndWeek));
+    }
+
+    private ScheduleEntry CreateTargetEntry(
+        CourseAdjustment adjustment,
+        Guid schedulePlanId)
+    {
+        var targetWeek = ResolveWeek(
+            adjustment.TeachingTask!.AcademicTerm!.StartDate,
+            adjustment.TargetDate!.Value);
+        return new ScheduleEntry
+        {
+            SchedulePlanId = schedulePlanId,
+            TeachingTaskId = adjustment.TeachingTaskId,
+            ClassroomId = adjustment.ClassroomId ?? adjustment.SourceClassroomId,
+            DayOfWeek = ToIsoDayOfWeek(adjustment.TargetDate.Value.DayOfWeek),
+            StartPeriod = adjustment.StartPeriod!.Value,
+            PeriodCount = adjustment.SourcePeriodCount!.Value,
+            StartWeek = targetWeek,
+            EndWeek = targetWeek,
+            WeekPattern = WeekPattern.All,
+            Notes = adjustment.Type == CourseAdjustmentType.Reschedule
+                ? $"调课（原第 {adjustment.SourceWeek} 周）"
+                : $"补课（对应原第 {adjustment.SourceWeek} 周课次）"
+        };
+    }
+
+    private static ScheduleEntry CloneEntry(
+        ScheduleEntry source,
+        int startWeek,
+        int endWeek) => new()
+    {
+        SchedulePlanId = source.SchedulePlanId,
+        TeachingTaskId = source.TeachingTaskId,
+        ClassroomId = source.ClassroomId,
+        DayOfWeek = source.DayOfWeek,
+        StartPeriod = source.StartPeriod,
+        PeriodCount = source.PeriodCount,
+        StartWeek = startWeek,
+        EndWeek = endWeek,
+        WeekPattern = source.WeekPattern,
+        Notes = source.Notes
+    };
+
+    private static bool RequiresSourceOccurrence(CourseAdjustmentType type) =>
+        type is CourseAdjustmentType.Reschedule or
+            CourseAdjustmentType.Cancel or
+            CourseAdjustmentType.Makeup;
+
+    private static bool IncludesWeek(WeekPattern pattern, int week) =>
+        pattern == WeekPattern.All ||
+        pattern == WeekPattern.Odd && week % 2 == 1 ||
+        pattern == WeekPattern.Even && week % 2 == 0;
+
+    private static bool HasIncludedWeek(WeekPattern pattern, int startWeek, int endWeek) =>
+        Enumerable.Range(startWeek, endWeek - startWeek + 1)
+            .Any(week => IncludesWeek(pattern, week));
+
+    private static DateOnly ResolveDate(DateOnly termStartDate, int week, int dayOfWeek)
+    {
+        var startDay = (int)termStartDate.DayOfWeek;
+        var daysSinceMonday = (startDay + 6) % 7;
+        var firstWeekMonday = termStartDate.AddDays(-daysSinceMonday);
+        return firstWeekMonday.AddDays((week - 1) * 7 + dayOfWeek - 1);
+    }
+
+    private static int ResolveWeek(DateOnly termStartDate, DateOnly date)
+    {
+        var startDay = (int)termStartDate.DayOfWeek;
+        var daysSinceMonday = (startDay + 6) % 7;
+        var firstWeekMonday = termStartDate.AddDays(-daysSinceMonday);
+        return (date.DayNumber - firstWeekMonday.DayNumber) / 7 + 1;
+    }
+
+    private static int ToIsoDayOfWeek(DayOfWeek dayOfWeek) =>
+        dayOfWeek == System.DayOfWeek.Sunday ? 7 : (int)dayOfWeek;
+
+    private IQueryable<TeachingTask> AccessibleTeachingTasks()
+    {
+        var source = db.TeachingTasks.AsQueryable();
+        var scope = currentUserDataScope.Current;
+        if (scope.Scope == DataScope.All) return source;
+        if (scope.Scope == DataScope.College)
+            return source.Where(x =>
+                x.Course!.CollegeId == scope.RestrictedCollegeId);
+        if (scope.IsInRole(SystemRoles.Teacher))
+            return source.Where(x =>
+                x.Teachers.Any(item => item.Teacher!.UserId == scope.UserId));
+        return source.Where(_ => false);
+    }
+
+    private System.Linq.Expressions.Expression<
         Func<CourseAdjustment, object>> AdjustmentProjection() => x => new
     {
         x.Id,
@@ -449,6 +808,17 @@ public sealed class CourseAdjustmentsController(
         x.Status,
         x.Reason,
         x.ReviewComment,
+        x.SourceScheduleEntryId,
+        x.SourceWeek,
+        x.SourceDate,
+        x.SourceStartPeriod,
+        x.SourcePeriodCount,
+        SourceClassroomName = x.SourceClassroomId == null
+            ? null
+            : db.Classrooms
+                .Where(room => room.Id == x.SourceClassroomId)
+                .Select(room => room.Building!.Name + " " + room.Name)
+                .FirstOrDefault(),
         x.TargetDate,
         x.DayOfWeek,
         x.StartPeriod,
@@ -464,6 +834,12 @@ public sealed class CourseAdjustmentsController(
         x.CreatedAt
     };
 
+    private sealed record SourceOccurrence(
+        ScheduleEntry Entry,
+        AcademicTerm Term,
+        int Week,
+        DateOnly Date);
+
     private ActionResult ConflictProblem(string detail) =>
         Conflict(new ProblemDetails
         {
@@ -487,7 +863,9 @@ public sealed record CourseAdjustmentRequest(
     Guid? ClassroomId,
     Guid? SubstituteTeacherId,
     int? CancelWeek,
-    DateOnly? CancelDate);
+    DateOnly? CancelDate,
+    Guid? SourceScheduleEntryId = null,
+    int? SourceWeek = null);
 
 public sealed record RejectionRequest(
     [MaxLength(500)] string? Comment);

src/Jiaowu.Api/Controllers/CoursesController.cs

@@ -3,6 +3,7 @@ using Jiaowu.Api.Contracts;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
@@ -15,7 +16,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/courses")]
 public sealed class CoursesController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache cache) : ControllerBase
 {
     private const string WriteRoles =
         SystemRoles.SuperAdmin + "," +
@@ -82,6 +84,17 @@ public sealed class CoursesController(
                 x.Nature,
                 x.AssessmentMethod,
                 x.Description,
+                PrerequisiteCourseIds = x.Prerequisites
+                    .OrderBy(item => item.PrerequisiteCourse!.Code)
+                    .Select(item => item.PrerequisiteCourseId),
+                Prerequisites = x.Prerequisites
+                    .OrderBy(item => item.PrerequisiteCourse!.Code)
+                    .Select(item => new
+                    {
+                        item.PrerequisiteCourseId,
+                        item.PrerequisiteCourse!.Code,
+                        item.PrerequisiteCourse.Name
+                    }),
                 x.IsEnabled,
                 x.SortOrder,
                 x.CreatedAt,
@@ -132,6 +145,8 @@ public sealed class CoursesController(
                  CategoryName = x.CourseCategory != null ? x.CourseCategory.Name : null,
                  x.Credits,
                  x.TotalHours,
+                 x.LectureHours,
+                 x.PracticeHours,
                  x.Nature,
                 x.AssessmentMethod
             })
@@ -144,9 +159,6 @@ public sealed class CoursesController(
         CourseRequest request,
         CancellationToken cancellationToken)
     {
-        var validation = await ValidateAsync(request, cancellationToken);
-        if (validation is not null) return validation;
-
         var entity = new Course
         {
             Code = request.Code.Trim(),
@@ -164,6 +176,16 @@ public sealed class CoursesController(
             IsEnabled = request.IsEnabled,
             SortOrder = request.SortOrder
         };
+        var validation = await ValidateAsync(entity.Id, request, cancellationToken);
+        if (validation is not null) return validation;
+
+        entity.Prerequisites = NormalizePrerequisiteIds(request)
+            .Select(prerequisiteId => new CoursePrerequisite
+            {
+                CourseId = entity.Id,
+                PrerequisiteCourseId = prerequisiteId
+            })
+            .ToList();
         db.Courses.Add(entity);
         return await SaveAsync(entity.Id, true, cancellationToken);
     }
@@ -175,10 +197,12 @@ public sealed class CoursesController(
         CourseRequest request,
         CancellationToken cancellationToken)
     {
-        var entity = await db.Courses.FindAsync([id], cancellationToken);
+        var entity = await db.Courses
+            .Include(x => x.Prerequisites)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
         if (entity is null) return NotFound();
         if (!CanManage(entity.CollegeId, entity.Nature)) return Forbid();
-        var validation = await ValidateAsync(request, cancellationToken);
+        var validation = await ValidateAsync(id, request, cancellationToken);
         if (validation is not null) return validation;
 
         entity.Code = request.Code.Trim();
@@ -195,6 +219,19 @@ public sealed class CoursesController(
         entity.Description = Normalize(request.Description);
         entity.IsEnabled = request.IsEnabled;
         entity.SortOrder = request.SortOrder;
+        var prerequisiteIds = NormalizePrerequisiteIds(request).ToHashSet();
+        db.CoursePrerequisites.RemoveRange(
+            entity.Prerequisites.Where(x =>
+                !prerequisiteIds.Contains(x.PrerequisiteCourseId)));
+        foreach (var prerequisiteId in prerequisiteIds.Except(
+                     entity.Prerequisites.Select(x => x.PrerequisiteCourseId)))
+        {
+            entity.Prerequisites.Add(new CoursePrerequisite
+            {
+                CourseId = entity.Id,
+                PrerequisiteCourseId = prerequisiteId
+            });
+        }
         return await SaveAsync(entity.Id, false, cancellationToken);
     }
 
@@ -210,6 +247,7 @@ public sealed class CoursesController(
     }
 
     private async Task<ActionResult?> ValidateAsync(
+        Guid courseId,
         CourseRequest request,
         CancellationToken cancellationToken)
     {
@@ -222,9 +260,62 @@ public sealed class CoursesController(
             return ValidationProblem("所选课程分类不存在或已停用。");
         if (request.LectureHours + request.PracticeHours > request.TotalHours)
             return ValidationProblem("讲授学时与实践学时之和不能超过总学时。");
+
+        var prerequisiteIds = NormalizePrerequisiteIds(request).ToArray();
+        if (prerequisiteIds.Contains(courseId))
+            return ValidationProblem("课程不能把自身设置为先修课程。");
+        var accessiblePrerequisiteCount = await ScopedCourses()
+            .CountAsync(x =>
+                prerequisiteIds.Contains(x.Id) &&
+                x.IsEnabled,
+                cancellationToken);
+        if (accessiblePrerequisiteCount != prerequisiteIds.Length)
+            return ValidationProblem("包含不存在、已停用或不在当前数据范围内的先修课程。");
+        if (await CreatesPrerequisiteCycleAsync(
+                courseId,
+                prerequisiteIds,
+                cancellationToken))
+            return ValidationProblem("先修关系不能形成循环依赖。");
         return null;
     }
 
+    private async Task<bool> CreatesPrerequisiteCycleAsync(
+        Guid courseId,
+        IReadOnlyCollection<Guid> prerequisiteIds,
+        CancellationToken cancellationToken)
+    {
+        if (prerequisiteIds.Count == 0) return false;
+
+        var edges = await db.CoursePrerequisites.AsNoTracking()
+            .Where(x => x.CourseId != courseId)
+            .Select(x => new { x.CourseId, x.PrerequisiteCourseId })
+            .ToListAsync(cancellationToken);
+        var prerequisitesByCourse = edges
+            .GroupBy(x => x.CourseId)
+            .ToDictionary(
+                group => group.Key,
+                group => group.Select(x => x.PrerequisiteCourseId).ToArray());
+
+        foreach (var prerequisiteId in prerequisiteIds)
+        {
+            var pending = new Stack<Guid>();
+            var visited = new HashSet<Guid>();
+            pending.Push(prerequisiteId);
+            while (pending.TryPop(out var candidate))
+            {
+                if (candidate == courseId) return true;
+                if (!visited.Add(candidate) ||
+                    !prerequisitesByCourse.TryGetValue(candidate, out var next))
+                    continue;
+                foreach (var item in next) pending.Push(item);
+            }
+        }
+        return false;
+    }
+
+    private static IEnumerable<Guid> NormalizePrerequisiteIds(CourseRequest request) =>
+        (request.PrerequisiteCourseIds ?? []).Distinct();
+
     private IQueryable<Course> ScopedCourses()
     {
         var scope = currentUserDataScope.Current;
@@ -273,6 +364,7 @@ public sealed class CoursesController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
             return created ? Created(string.Empty, new { id }) : NoContent();
         }
         catch (DbUpdateException)
@@ -304,4 +396,5 @@ public sealed record CourseRequest(
     AssessmentMethod AssessmentMethod,
     [MaxLength(1000)] string? Description,
     bool IsEnabled,
-    int SortOrder);
+    int SortOrder,
+    IReadOnlyCollection<Guid>? PrerequisiteCourseIds = null);

src/Jiaowu.Api/Controllers/CoursesExcelController.cs

@@ -2,6 +2,7 @@ using System.Globalization;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
@@ -15,7 +16,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/courses")]
 public sealed class CoursesExcelController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache cache) : ControllerBase
 {
     private const string WriteRoles =
         SystemRoles.SuperAdmin + "," +
@@ -141,6 +143,9 @@ public sealed class CoursesExcelController(
 
                     await db.SaveChangesAsync(cancellationToken);
                     await transaction.CommitAsync(cancellationToken);
+                    await cache.RemoveByTagAsync(
+                        AppCacheTags.Timetables,
+                        cancellationToken);
                     return Ok(result);
                 }
                 catch (DbUpdateException)

src/Jiaowu.Api/Controllers/DashboardController.cs

@@ -1,4 +1,6 @@
 using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Auth;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
@@ -9,75 +11,303 @@ namespace Jiaowu.Api.Controllers;
 [ApiController]
 [Authorize]
 [Route("api/dashboard")]
-public sealed class DashboardController(AppDbContext db) : ControllerBase
+public sealed class DashboardController(
+    AppDbContext db,
+    ICurrentUserDataScope currentUserDataScope) : ControllerBase
 {
     [HttpGet]
-    public async Task<ActionResult<object>> Get(CancellationToken cancellationToken)
+    public async Task<ActionResult<DashboardResponse>> Get(
+        CancellationToken cancellationToken)
     {
+        var scope = currentUserDataScope.Current;
+        Guid? restrictedCollegeId = scope.Scope == DataScope.All
+            ? null
+            : scope.CollegeId ?? Guid.Empty;
+        var collegeName = restrictedCollegeId.HasValue &&
+                          restrictedCollegeId.Value != Guid.Empty
+            ? await db.Colleges.AsNoTracking()
+                .Where(x => x.Id == restrictedCollegeId.Value)
+                .Select(x => x.Name)
+                .FirstOrDefaultAsync(cancellationToken)
+            : null;
+
         var currentTerm = await db.AcademicTerms
             .AsNoTracking()
             .Where(x => x.IsCurrent)
-            .Select(x => new { x.Id, x.Name, x.StartDate, x.EndDate })
+            .Select(x => new DashboardTerm(
+                x.Id,
+                x.Name,
+                x.StartDate,
+                x.EndDate))
             .FirstOrDefaultAsync(cancellationToken);
+        var currentTermId = currentTerm?.Id;
 
-        return new
+        var students = db.Students.AsNoTracking()
-        {
+            .Where(x =>
-            CurrentTerm = currentTerm,
+                !restrictedCollegeId.HasValue ||
-            Counts = new
+                x.AdministrativeClass!.Major!.CollegeId ==
-            {
+                restrictedCollegeId.Value);
-                Campuses = await db.Campuses.CountAsync(cancellationToken),
+        var teachers = db.Teachers.AsNoTracking()
-                Colleges = await db.Colleges.CountAsync(cancellationToken),
+            .Where(x =>
-                Majors = await db.Majors.CountAsync(cancellationToken),
+                !restrictedCollegeId.HasValue ||
-                Classes = await db.AdministrativeClasses.CountAsync(cancellationToken),
+                x.CollegeId == restrictedCollegeId.Value);
-                Classrooms = await db.Classrooms.CountAsync(cancellationToken),
+        var courses = db.Courses.AsNoTracking()
-                Teachers = await db.Teachers.CountAsync(cancellationToken),
+            .Where(x =>
-                Students = await db.Students.CountAsync(cancellationToken),
+                !restrictedCollegeId.HasValue ||
-                Courses = await db.Courses.CountAsync(cancellationToken),
+                x.CollegeId == restrictedCollegeId.Value);
-                CurriculumPlans = await db.CurriculumPlans.CountAsync(cancellationToken),
+        var teachingTasks = db.TeachingTasks.AsNoTracking()
-                TeachingTasks = await db.TeachingTasks.CountAsync(cancellationToken),
+            .Where(x =>
-                SchedulePlans = await db.SchedulePlans.CountAsync(cancellationToken),
+                currentTermId.HasValue &&
-                CourseSelectionRounds = await db.CourseSelectionRounds
+                x.AcademicTermId == currentTermId.Value &&
-                    .CountAsync(cancellationToken),
+                (!restrictedCollegeId.HasValue ||
-                CourseSelectionOfferings = await db.CourseSelectionOfferings
+                 x.Course!.CollegeId == restrictedCollegeId.Value));
-                    .CountAsync(cancellationToken),
+        var gradeSheets = db.GradeSheets.AsNoTracking()
-                CourseEnrollments = await db.CourseEnrollments
+            .Where(x =>
-                    .CountAsync(
+                currentTermId.HasValue &&
-                        x => x.Status == CourseEnrollmentStatus.Enrolled,
+                x.TeachingTask!.AcademicTermId == currentTermId.Value &&
-                        cancellationToken),
+                (!restrictedCollegeId.HasValue ||
-                GradeSheets = await db.GradeSheets.CountAsync(cancellationToken),
+                 x.TeachingTask.Course!.CollegeId ==
-                PublishedGradeSheets = await db.GradeSheets.CountAsync(
+                 restrictedCollegeId.Value));
+        var enrollments = db.CourseEnrollments.AsNoTracking()
+            .Where(x =>
+                currentTermId.HasValue &&
+                x.Status == CourseEnrollmentStatus.Enrolled &&
+                x.CourseSelectionOffering!.CourseSelectionRound!
+                    .AcademicTermId == currentTermId.Value &&
+                (!restrictedCollegeId.HasValue ||
+                 x.CourseSelectionOffering.TeachingTask!.Course!.CollegeId ==
+                 restrictedCollegeId.Value));
+
+        var taskCount = await teachingTasks.CountAsync(cancellationToken);
+        var publishedTaskCount = await teachingTasks.CountAsync(
+            x => x.Status == TeachingTaskStatus.Published,
+            cancellationToken);
+        var scheduledTaskCount = currentTermId.HasValue
+            ? await db.ScheduleEntries.AsNoTracking()
+                .Where(x =>
+                    x.SchedulePlan!.AcademicTermId == currentTermId.Value &&
+                    x.SchedulePlan.Status == SchedulePlanStatus.Published &&
+                    (!restrictedCollegeId.HasValue ||
+                     x.TeachingTask!.Course!.CollegeId ==
+                     restrictedCollegeId.Value))
+                .Select(x => x.TeachingTaskId)
+                .Distinct()
+                .CountAsync(cancellationToken)
+            : 0;
+        var gradeSheetCount = await gradeSheets.CountAsync(cancellationToken);
+        var publishedGradeSheetCount = await gradeSheets.CountAsync(
             x => x.Status == GradeSheetStatus.Published,
+            cancellationToken);
+
+        var counts = new DashboardCounts(
+            await students.CountAsync(
+                x => x.Status == StudentStatus.Active,
                 cancellationToken),
-                GradeRecords = await db.GradeRecords.CountAsync(cancellationToken),
+            await teachers.CountAsync(
-                ExamPlans = await db.ExamPlans.CountAsync(cancellationToken),
+                x => x.Status == TeacherStatus.Active,
-                ExamSessions = await db.ExamSessions.CountAsync(cancellationToken),
-                StudentStatusChanges = await db.StudentStatusChanges
-                    .CountAsync(cancellationToken),
-                PendingStudentStatusChanges = await db.StudentStatusChanges.CountAsync(
-                    x => x.State == StudentStatusChangeState.Submitted ||
-                         x.State == StudentStatusChangeState.CounselorApproved ||
-                         x.State == StudentStatusChangeState.CollegeApproved,
                 cancellationToken),
-                GraduationAuditBatches = await db.GraduationAuditBatches
+            await courses.CountAsync(
-                    .CountAsync(cancellationToken),
+                x => x.IsEnabled,
-                PublishedGraduationAuditBatches = await db.GraduationAuditBatches
-                    .CountAsync(
-                        x => x.Status == GraduationAuditBatchStatus.Published,
                 cancellationToken),
-                DegreeAwardBatches = await db.DegreeAwardBatches
+            taskCount,
-                    .CountAsync(cancellationToken),
+            publishedTaskCount,
-                PublishedDegreeAwardBatches = await db.DegreeAwardBatches
+            scheduledTaskCount,
-                    .CountAsync(
+            await enrollments.CountAsync(cancellationToken),
-                        x => x.Status == DegreeAwardBatchStatus.Published,
+            gradeSheetCount,
+            publishedGradeSheetCount,
+            await gradeSheets.CountAsync(
+                x => x.Status == GradeSheetStatus.Submitted,
                 cancellationToken),
-                GraduationClearanceBatches = await db.GraduationClearanceBatches
+            currentTermId.HasValue
-                    .CountAsync(cancellationToken),
+                ? await db.CourseSelectionRounds.AsNoTracking().CountAsync(
-                OpenGraduationClearanceBatches = await db.GraduationClearanceBatches
+                    x => x.AcademicTermId == currentTermId.Value &&
-                    .CountAsync(
+                         x.Status == CourseSelectionRoundStatus.Open,
-                        x => x.Status == GraduationClearanceBatchStatus.Open,
+                    cancellationToken)
-                        cancellationToken),
+                : 0);
-                Users = await db.Users.CountAsync(cancellationToken)
+
+        var pending = await LoadPendingAsync(
+            scope,
+            restrictedCollegeId,
+            cancellationToken);
+
+        return Ok(new DashboardResponse(
+            BuildAudience(scope, collegeName),
+            currentTerm,
+            counts,
+            pending,
+            DateTime.UtcNow));
     }
-        };
+
+    private async Task<DashboardPending> LoadPendingAsync(
+        CurrentUserScope scope,
+        Guid? restrictedCollegeId,
+        CancellationToken cancellationToken)
+    {
+        var isSchoolManager =
+            scope.IsInRole(SystemRoles.SuperAdmin) ||
+            scope.IsInRole(SystemRoles.AcademicAdmin);
+        var isCollegeManager =
+            !isSchoolManager && scope.IsInRole(SystemRoles.CollegeAdmin);
+        if (!isSchoolManager && !isCollegeManager)
+            return new DashboardPending(0, 0, 0, 0, 0, 0, 0);
+
+        var teacherApplications = db.TeacherCourseApplications.AsNoTracking()
+            .Where(x =>
+                x.Status == TeacherCourseApplicationStatus.Pending &&
+                (!restrictedCollegeId.HasValue ||
+                 x.Teacher!.CollegeId == restrictedCollegeId.Value));
+        var gradeSheets = db.GradeSheets.AsNoTracking()
+            .Where(x =>
+                x.Status == GradeSheetStatus.Submitted &&
+                (!restrictedCollegeId.HasValue ||
+                 x.TeachingTask!.Course!.CollegeId ==
+                 restrictedCollegeId.Value));
+        var courseAdjustments = db.CourseAdjustments.AsNoTracking()
+            .Where(x =>
+                x.Status == CourseAdjustmentStatus.Submitted &&
+                (!restrictedCollegeId.HasValue ||
+                 x.TeachingTask!.Course!.CollegeId ==
+                 restrictedCollegeId.Value));
+        var studentStatusChanges = db.StudentStatusChanges.AsNoTracking()
+            .Where(x =>
+                x.State == (isCollegeManager
+                    ? StudentStatusChangeState.CounselorApproved
+                    : StudentStatusChangeState.CollegeApproved) &&
+                (!restrictedCollegeId.HasValue ||
+                 x.Student!.AdministrativeClass!.Major!.CollegeId ==
+                 restrictedCollegeId.Value));
+        var gradeModifications = db.GradeModifications.AsNoTracking()
+            .Where(x =>
+                x.Status == (isCollegeManager
+                    ? GradeModificationStatus.TeacherSubmitted
+                    : GradeModificationStatus.CollegeApproved) &&
+                (!restrictedCollegeId.HasValue ||
+                 x.GradeRecord!.GradeSheet!.TeachingTask!.Course!.CollegeId ==
+                 restrictedCollegeId.Value));
+
+        var generalApprovals =
+            await db.CourseExemptions.AsNoTracking().CountAsync(
+                x => x.Status == ApprovalStatus.Submitted &&
+                     (!restrictedCollegeId.HasValue ||
+                      x.TeachingTask!.Course!.CollegeId ==
+                      restrictedCollegeId.Value),
+                cancellationToken) +
+            await db.DeferredExams.AsNoTracking().CountAsync(
+                x => x.Status == ApprovalStatus.Submitted &&
+                     (!restrictedCollegeId.HasValue ||
+                      x.TeachingTask!.Course!.CollegeId ==
+                      restrictedCollegeId.Value),
+                cancellationToken) +
+            await db.CourseSubstitutions.AsNoTracking().CountAsync(
+                x => x.Status == ApprovalStatus.Submitted &&
+                     (!restrictedCollegeId.HasValue ||
+                      x.Student!.AdministrativeClass!.Major!.CollegeId ==
+                      restrictedCollegeId.Value),
+                cancellationToken) +
+            await db.AttendanceRecords.AsNoTracking().CountAsync(
+                x => x.AppealStatus == AttendanceAppealStatus.Pending &&
+                     (!restrictedCollegeId.HasValue ||
+                      x.Student!.AdministrativeClass!.Major!.CollegeId ==
+                      restrictedCollegeId.Value),
+                cancellationToken);
+
+        var classroomReservations = isCollegeManager &&
+                                    restrictedCollegeId.HasValue
+            ? await db.ClassroomReservations.AsNoTracking().CountAsync(
+                x => x.Status == ClassroomReservationStatus.Submitted &&
+                     x.ApplicantCollegeId == restrictedCollegeId.Value,
+                cancellationToken)
+            : 0;
+
+        return new DashboardPending(
+            await teacherApplications.CountAsync(cancellationToken),
+            await gradeSheets.CountAsync(cancellationToken),
+            await courseAdjustments.CountAsync(cancellationToken),
+            await studentStatusChanges.CountAsync(cancellationToken),
+            await gradeModifications.CountAsync(cancellationToken),
+            classroomReservations,
+            generalApprovals);
+    }
+
+    private static DashboardAudience BuildAudience(
+        CurrentUserScope scope,
+        string? collegeName)
+    {
+        if (scope.IsInRole(SystemRoles.SuperAdmin))
+            return new DashboardAudience(
+                "System",
+                "全域教务工作台",
+                "全校",
+                "统筹基础数据、教学运行与系统治理");
+        if (scope.IsInRole(SystemRoles.AcademicAdmin))
+            return new DashboardAudience(
+                "School",
+                "校级教务工作台",
+                "全校",
+                "聚焦跨学院教学运行与校级审核");
+        if (scope.IsInRole(SystemRoles.CollegeAdmin))
+            return new DashboardAudience(
+                "College",
+                "学院教务工作台",
+                collegeName ?? "本学院",
+                "聚焦本学院教学准备、过程审核与成绩归档");
+        if (scope.IsInRole(SystemRoles.Leader))
+            return new DashboardAudience(
+                "Leadership",
+                "教学运行观察台",
+                "全校",
+                "查看全校教学运行与质量数据");
+        if (scope.IsInRole(SystemRoles.Counselor))
+            return new DashboardAudience(
+                "Counselor",
+                "班级工作台",
+                collegeName ?? "所辖班级",
+                "处理学生过程管理与学业支持");
+        return new DashboardAudience(
+            "Teaching",
+            "教学工作台",
+            collegeName ?? "个人教学",
+            "查看课程运行并进入日常教学工作");
     }
 }
+
+public sealed record DashboardResponse(
+    DashboardAudience Audience,
+    DashboardTerm? CurrentTerm,
+    DashboardCounts Counts,
+    DashboardPending Pending,
+    DateTime GeneratedAt);
+
+public sealed record DashboardAudience(
+    string Level,
+    string Title,
+    string ScopeName,
+    string Description);
+
+public sealed record DashboardTerm(
+    Guid Id,
+    string Name,
+    DateOnly StartDate,
+    DateOnly EndDate);
+
+public sealed record DashboardCounts(
+    int Students,
+    int Teachers,
+    int Courses,
+    int TeachingTasks,
+    int PublishedTeachingTasks,
+    int ScheduledTeachingTasks,
+    int CourseEnrollments,
+    int GradeSheets,
+    int PublishedGradeSheets,
+    int SubmittedGradeSheets,
+    int OpenCourseSelectionRounds);
+
+public sealed record DashboardPending(
+    int TeacherApplications,
+    int GradeSheets,
+    int CourseAdjustments,
+    int StudentStatusChanges,
+    int GradeModifications,
+    int ClassroomReservations,
+    int GeneralApprovals);

src/Jiaowu.Api/Controllers/DegreeAwardsController.cs

@@ -60,8 +60,16 @@ public sealed class DegreeAwardsController(
 
     [HttpGet("batches/{id:guid}")]
     [Authorize(Roles = Reviewers)]
-    public async Task<ActionResult> GetBatch(Guid id, CancellationToken token)
+    public async Task<ActionResult> GetBatch(
+        Guid id,
+        [FromQuery] int page = 1,
+        [FromQuery] int pageSize = 20,
+        [FromQuery] string? keyword = null,
+        [FromQuery] DegreeAwardConclusion? conclusion = null,
+        CancellationToken token = default)
     {
+        page = Math.Max(page, 1);
+        pageSize = Math.Clamp(pageSize, 10, 100);
         var batch = await db.DegreeAwardBatches.AsNoTracking()
             .FirstOrDefaultAsync(x => x.Id == id, token);
         if (batch is null) return NotFound();
@@ -71,18 +79,34 @@ public sealed class DegreeAwardsController(
         if (collegeId.HasValue)
             source = source.Where(x =>
                 x.Student!.AdministrativeClass!.Major!.CollegeId == collegeId);
-        return Ok(new
+
+        var summary = await source
+            .GroupBy(_ => 1)
+            .Select(group => new
             {
-            batch.Id,
+                ResultCount = group.Count(),
-            batch.Name,
+                GrantedCount = group.Count(x =>
-            batch.GraduationYear,
+                    x.Conclusion == DegreeAwardConclusion.Granted),
-            batch.DegreeName,
+                NotGrantedCount = group.Count(x =>
-            batch.MinimumGradePoint,
+                    x.Conclusion == DegreeAwardConclusion.NotGranted),
-            batch.Status,
+                OverrideCount = group.Count(x => x.IsOverridden)
-            batch.Notes,
+            })
-            batch.CalculatedAt,
+            .FirstOrDefaultAsync(token);
-            batch.PublishedAt,
+
-            Results = await source.OrderBy(x => x.Student!.StudentNumber)
+        var normalizedKeyword = keyword?.Trim();
+        if (!string.IsNullOrWhiteSpace(normalizedKeyword))
+            source = source.Where(x =>
+                x.Student!.StudentNumber.Contains(normalizedKeyword) ||
+                x.Student.Name.Contains(normalizedKeyword) ||
+                x.Student.AdministrativeClass!.Name.Contains(normalizedKeyword) ||
+                x.Student.AdministrativeClass.Major!.Name.Contains(normalizedKeyword));
+        if (conclusion.HasValue)
+            source = source.Where(x => x.Conclusion == conclusion.Value);
+
+        var total = await source.CountAsync(token);
+        var items = await source.OrderBy(x => x.Student!.StudentNumber)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
             .Select(x => new
             {
                 x.Id,
@@ -99,7 +123,30 @@ public sealed class DegreeAwardsController(
                 x.IsOverridden,
                 x.ReviewComment,
                 x.ReviewedAt
-                }).ToListAsync(token)
+            }).ToListAsync(token);
+
+        return Ok(new
+        {
+            batch.Id,
+            batch.Name,
+            batch.GraduationYear,
+            batch.DegreeName,
+            batch.MinimumGradePoint,
+            batch.Status,
+            batch.Notes,
+            batch.CalculatedAt,
+            batch.PublishedAt,
+            ResultCount = summary?.ResultCount ?? 0,
+            GrantedCount = summary?.GrantedCount ?? 0,
+            NotGrantedCount = summary?.NotGrantedCount ?? 0,
+            OverrideCount = summary?.OverrideCount ?? 0,
+            Results = new
+            {
+                Items = items,
+                Total = total,
+                Page = page,
+                PageSize = pageSize
+            }
         });
     }
 
@@ -133,25 +180,30 @@ public sealed class DegreeAwardsController(
             return ConflictProblem("已发布批次不能重新计算。");
 
         var auditCandidates = await db.GraduationAuditResults.AsNoTracking()
-            .Include(x => x.GraduationAuditBatch)
-            .Include(x => x.Student)
-            .ThenInclude(x => x!.AdministrativeClass)
-            .ThenInclude(x => x!.Major)
             .Where(x =>
                 x.GraduationAuditBatch!.GraduationYear == batch.GraduationYear &&
                 x.GraduationAuditBatch.Status == GraduationAuditBatchStatus.Published &&
                 x.Conclusion == GraduationAuditConclusion.Eligible)
             .OrderByDescending(x => x.GraduationAuditBatch!.PublishedAt)
+            .Select(x => new
+            {
+                x.Id,
+                x.StudentId,
+                StudentStatus = x.Student!.Status
+            })
             .ToListAsync(token);
         var audits = auditCandidates
             .GroupBy(x => x.StudentId)
             .Select(x => x.First())
             .ToList();
-        var studentIds = audits.Select(x => x.StudentId).ToArray();
         var gradePoints = await db.GradeRecords.AsNoTracking()
             .Where(x => x.GradeSheet!.Status == GradeSheetStatus.Published &&
                         x.GradePoint.HasValue)
-            .WhereIn(studentIds, x => x.StudentId)
+            .Where(x => db.GraduationAuditResults.Any(audit =>
+                audit.StudentId == x.StudentId &&
+                audit.GraduationAuditBatch!.GraduationYear == batch.GraduationYear &&
+                audit.GraduationAuditBatch.Status == GraduationAuditBatchStatus.Published &&
+                audit.Conclusion == GraduationAuditConclusion.Eligible))
             .Select(x => new
             {
                 x.StudentId,
@@ -159,14 +211,17 @@ public sealed class DegreeAwardsController(
                 x.GradeSheet!.TeachingTask!.Course!.Credits
             }).ToListAsync(token);
 
-        var oldResults = await db.DegreeAwardResults
+        var gradePointsByStudent = gradePoints
-            .Where(x => x.DegreeAwardBatchId == id).ToListAsync(token);
+            .GroupBy(x => x.StudentId)
-        db.DegreeAwardResults.RemoveRange(oldResults);
+            .ToDictionary(group => group.Key, group => group.ToList());
-        await db.SaveChangesAsync(token);
+
+        await db.DegreeAwardResults
+            .Where(x => x.DegreeAwardBatchId == id)
+            .ExecuteDeleteAsync(token);
 
         foreach (var audit in audits)
         {
-            var grades = gradePoints.Where(x => x.StudentId == audit.StudentId).ToList();
+            var grades = gradePointsByStudent.GetValueOrDefault(audit.StudentId) ?? [];
             var credits = grades.Sum(x => x.Credits);
             var average = credits == 0
                 ? 0
@@ -175,8 +230,8 @@ public sealed class DegreeAwardsController(
                     2,
                     MidpointRounding.AwayFromZero);
             var conclusion = DegreeAwardRules.Evaluate(
-                true, audit.Student!.Status, average, batch.MinimumGradePoint);
+                true, audit.StudentStatus, average, batch.MinimumGradePoint);
-            var reason = audit.Student.Status != StudentStatus.Graduated
+            var reason = audit.StudentStatus != StudentStatus.Graduated
                 ? "学籍状态尚未转为毕业"
                 : average < batch.MinimumGradePoint
                     ? $"平均绩点 {average:0.00}，低于批次要求 {batch.MinimumGradePoint:0.00}"

src/Jiaowu.Api/Controllers/ExperimentGradesController.cs

@@ -0,0 +1,945 @@
+using System.ComponentModel.DataAnnotations;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Grades;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Teaching;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Controllers;
+
+[ApiController]
+[Authorize]
+[Route("api/experiment-grades")]
+public sealed class ExperimentGradesController(
+    AppDbContext db,
+    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+{
+    private const string Managers =
+        SystemRoles.SuperAdmin + "," +
+        SystemRoles.AcademicAdmin + "," +
+        SystemRoles.CollegeAdmin + "," +
+        SystemRoles.Teacher;
+
+    private const string Reviewers =
+        SystemRoles.SuperAdmin + "," +
+        SystemRoles.AcademicAdmin + "," +
+        SystemRoles.CollegeAdmin;
+
+    private const string Publishers =
+        SystemRoles.SuperAdmin + "," +
+        SystemRoles.AcademicAdmin;
+
+    [HttpGet("management")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> GetManagement(
+        Guid? academicTermId,
+        ExperimentGradeSheetStatus? status,
+        CancellationToken cancellationToken)
+    {
+        var source = ScopedProjects().AsNoTracking()
+            .Where(x =>
+                x.Status == ExperimentProjectStatus.Published ||
+                x.Status == ExperimentProjectStatus.Closed);
+        if (academicTermId.HasValue)
+            source = source.Where(x =>
+                x.TeachingTask!.AcademicTermId == academicTermId);
+        if (status.HasValue)
+            source = source.Where(x =>
+                x.GradeSheet != null &&
+                x.GradeSheet.Status == status.Value);
+
+        return Ok(await source
+            .OrderByDescending(x => x.TeachingTask!.AcademicTerm!.StartDate)
+            .ThenBy(x => x.TeachingTask!.TaskNumber)
+            .ThenBy(x => x.Code)
+            .Select(x => new
+            {
+                x.Id,
+                x.Code,
+                x.Name,
+                x.ArrangementMode,
+                ProjectStatus = x.Status,
+                x.TeachingTaskId,
+                x.TeachingTask!.TaskNumber,
+                TaskName = x.TeachingTask.Name,
+                AcademicTermId = x.TeachingTask.AcademicTermId,
+                TermName = x.TeachingTask.AcademicTerm!.Name,
+                CourseCode = x.TeachingTask.Course!.Code,
+                CourseName = x.TeachingTask.Course.Name,
+                CollegeName = x.TeachingTask.Course.College!.Name,
+                TeacherNames = x.TeachingTask.Teachers
+                    .OrderByDescending(item => item.IsPrimary)
+                    .Select(item => item.Teacher!.Name),
+                Sheet = x.GradeSheet == null
+                    ? null
+                    : new
+                    {
+                        x.GradeSheet.Id,
+                        x.GradeSheet.Status,
+                        x.GradeSheet.ContributionWeight,
+                        x.GradeSheet.PassScore,
+                        ItemCount = x.GradeSheet.Items.Count,
+                        StudentCount = x.GradeSheet.Records.Count,
+                        CompletedCount = x.GradeSheet.Records.Count(record =>
+                            record.ParticipationStatus !=
+                                ExperimentParticipationStatus.Pending),
+                        ScoredCount = x.GradeSheet.Records.Count(record =>
+                            record.TotalScore != null),
+                        PassedCount = x.GradeSheet.Records.Count(record =>
+                            record.IsPassed == true),
+                        x.GradeSheet.SubmittedAt,
+                        x.GradeSheet.ReviewedAt,
+                        x.GradeSheet.PublishedAt
+                    }
+            })
+            .ToListAsync(cancellationToken));
+    }
+
+    [HttpGet("mine")]
+    [Authorize(Roles = SystemRoles.Student)]
+    public async Task<ActionResult> GetMine(CancellationToken cancellationToken)
+    {
+        var student = await CurrentStudentAsync(cancellationToken);
+        if (student is null)
+            return ConflictProblem("当前账号未关联有效学生档案。");
+
+        return Ok(await db.ExperimentGradeRecords.AsNoTracking()
+            .Where(x =>
+                x.StudentId == student.Id &&
+                x.ExperimentGradeSheet!.Status ==
+                    ExperimentGradeSheetStatus.Published)
+            .OrderByDescending(x =>
+                x.ExperimentGradeSheet!.PublishedAt)
+            .ThenBy(x =>
+                x.ExperimentGradeSheet!.ExperimentProject!.Code)
+            .Select(x => new
+            {
+                x.Id,
+                x.ExperimentGradeSheetId,
+                ProjectId = x.ExperimentGradeSheet!.ExperimentProjectId,
+                ProjectCode =
+                    x.ExperimentGradeSheet.ExperimentProject!.Code,
+                ProjectName =
+                    x.ExperimentGradeSheet.ExperimentProject.Name,
+                x.ExperimentGradeSheet.ExperimentProject.ArrangementMode,
+                CourseCode = x.ExperimentGradeSheet.ExperimentProject
+                    .TeachingTask!.Course!.Code,
+                CourseName = x.ExperimentGradeSheet.ExperimentProject
+                    .TeachingTask.Course.Name,
+                TermName = x.ExperimentGradeSheet.ExperimentProject
+                    .TeachingTask.AcademicTerm!.Name,
+                x.ExperimentGradeSheet.PassScore,
+                x.ParticipationStatus,
+                x.TotalScore,
+                x.IsPassed,
+                x.SafetyViolation,
+                x.AttemptNumber,
+                x.SubmissionReference,
+                x.SubmittedAt,
+                x.IsLate,
+                x.TeacherComment,
+                Items = x.ItemScores
+                    .OrderBy(score =>
+                        score.ExperimentGradeItem!.SortOrder)
+                    .Select(score => new
+                    {
+                        score.ExperimentGradeItemId,
+                        score.ExperimentGradeItem!.Name,
+                        score.ExperimentGradeItem.Kind,
+                        score.ExperimentGradeItem.Weight,
+                        score.Score,
+                        score.Comment
+                    }),
+                x.ExperimentGradeSheet.PublishedAt
+            })
+            .ToListAsync(cancellationToken));
+    }
+
+    [HttpPost("sheets")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> CreateSheet(
+        ExperimentGradeSheetRequest request,
+        CancellationToken cancellationToken)
+    {
+        var items = BuildItems(request.Items);
+        if (!ExperimentGradeCalculator.AreWeightsValid(
+                request.ContributionWeight,
+                request.PassScore,
+                items))
+            return ValidationProblem(
+                "实验评分项至少设置一项、权重合计 100%，项目贡献权重应大于 0。");
+
+        var project = await ScopedProjects()
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x =>
+                x.Id == request.ExperimentProjectId,
+                cancellationToken);
+        if (project is null) return NotFound();
+        if (project.Status is not (
+                ExperimentProjectStatus.Published or
+                ExperimentProjectStatus.Closed))
+            return ConflictProblem("只有已发布或已关闭实验项目可以建立成绩单。");
+        if (!CanInitialize(project.TeachingTask!)) return Forbid();
+        if (await db.ExperimentGradeSheets.AnyAsync(x =>
+                x.ExperimentProjectId == project.Id,
+                cancellationToken))
+            return ConflictProblem("该实验项目已经建立成绩单。");
+
+        var participants = await LoadParticipantsAsync(
+            project,
+            cancellationToken);
+        if (participants.Count == 0)
+            return ConflictProblem("实验项目当前没有可评分学生。");
+
+        var sheet = new ExperimentGradeSheet
+        {
+            ExperimentProjectId = project.Id,
+            ContributionWeight = request.ContributionWeight,
+            PassScore = request.PassScore,
+            Items = items,
+            Records = participants.Select(participant =>
+                new ExperimentGradeRecord
+                {
+                    StudentId = participant.StudentId,
+                    ExperimentSessionId = participant.SessionId,
+                    ItemScores = items.Select(item =>
+                        new ExperimentGradeItemScore
+                        {
+                            ExperimentGradeItemId = item.Id
+                        }).ToList()
+                }).ToList()
+        };
+        db.ExperimentGradeSheets.Add(sheet);
+        await db.SaveChangesAsync(cancellationToken);
+        return Created(string.Empty, new { sheet.Id });
+    }
+
+    [HttpGet("sheets/{id:guid}")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> GetSheet(
+        Guid id,
+        int recordPage = 1,
+        int recordPageSize = 50,
+        string? studentKeyword = null,
+        CancellationToken cancellationToken = default)
+    {
+        recordPage = Math.Max(1, recordPage);
+        recordPageSize = Math.Clamp(recordPageSize, 10, 100);
+        studentKeyword = string.IsNullOrWhiteSpace(studentKeyword)
+            ? null
+            : studentKeyword.Trim();
+
+        var sheet = await ScopedSheets().AsNoTracking()
+            .Where(x => x.Id == id)
+            .Select(x => new
+            {
+                x.Id,
+                x.ExperimentProjectId,
+                ProjectCode = x.ExperimentProject!.Code,
+                ProjectName = x.ExperimentProject.Name,
+                x.ExperimentProject.ArrangementMode,
+                x.ExperimentProject.TeachingTaskId,
+                x.ExperimentProject.TeachingTask!.TaskNumber,
+                TaskName = x.ExperimentProject.TeachingTask.Name,
+                AcademicTermId =
+                    x.ExperimentProject.TeachingTask.AcademicTermId,
+                TermName = x.ExperimentProject.TeachingTask
+                    .AcademicTerm!.Name,
+                CourseCollegeId = x.ExperimentProject.TeachingTask
+                    .Course!.CollegeId,
+                CourseCollegeName = x.ExperimentProject.TeachingTask
+                    .Course.College!.Name,
+                CourseCode =
+                    x.ExperimentProject.TeachingTask.Course.Code,
+                CourseName =
+                    x.ExperimentProject.TeachingTask.Course.Name,
+                TeacherNames = x.ExperimentProject.TeachingTask.Teachers
+                    .OrderByDescending(item => item.IsPrimary)
+                    .Select(item => item.Teacher!.Name),
+                x.ContributionWeight,
+                x.PassScore,
+                Items = x.Items.OrderBy(item => item.SortOrder)
+                    .Select(item => new
+                    {
+                        item.Id,
+                        item.Name,
+                        item.Kind,
+                        item.Weight
+                    }),
+                x.Status,
+                x.ReviewComment,
+                x.SubmittedAt,
+                x.ReviewedAt,
+                x.PublishedAt,
+                x.CreatedAt,
+                x.UpdatedAt
+            })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (sheet is null) return NotFound();
+
+        var recordsSource = db.ExperimentGradeRecords.AsNoTracking()
+            .Where(x => x.ExperimentGradeSheetId == id);
+        if (studentKeyword is not null)
+            recordsSource = recordsSource.Where(x =>
+                x.Student!.StudentNumber.Contains(studentKeyword) ||
+                x.Student.Name.Contains(studentKeyword) ||
+                x.Student.AdministrativeClass!.Name.Contains(studentKeyword));
+        var recordTotal = await recordsSource.CountAsync(cancellationToken);
+        var records = await recordsSource
+            .OrderBy(x => x.Student!.StudentNumber)
+            .Skip((recordPage - 1) * recordPageSize)
+            .Take(recordPageSize)
+            .Select(x => new
+            {
+                x.Id,
+                x.StudentId,
+                x.Student!.StudentNumber,
+                x.Student.Name,
+                ClassName = x.Student.AdministrativeClass!.Name,
+                x.ExperimentSessionId,
+                Session = x.ExperimentSession == null
+                    ? null
+                    : new
+                    {
+                        x.ExperimentSession.SessionDate,
+                        x.ExperimentSession.StartPeriod,
+                        x.ExperimentSession.PeriodCount,
+                        ClassroomName =
+                            x.ExperimentSession.Classroom!.Name
+                    },
+                x.ParticipationStatus,
+                x.TotalScore,
+                x.IsPassed,
+                x.SafetyViolation,
+                x.AttemptNumber,
+                x.SubmissionReference,
+                x.SubmittedAt,
+                x.IsLate,
+                x.TeacherComment,
+                ItemScores = x.ItemScores
+                    .OrderBy(score =>
+                        score.ExperimentGradeItem!.SortOrder)
+                    .Select(score => new
+                    {
+                        score.ExperimentGradeItemId,
+                        score.ExperimentGradeItem!.Name,
+                        score.Score,
+                        score.Comment
+                    }),
+                x.UpdatedAt
+            })
+            .ToListAsync(cancellationToken);
+
+        var task = await db.TeachingTasks.AsNoTracking()
+            .Include(x => x.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .SingleAsync(
+                x => x.Id == sheet.TeachingTaskId,
+                cancellationToken);
+        var canReview = CanReviewCollege(sheet.CourseCollegeId) &&
+                        sheet.Status ==
+                            ExperimentGradeSheetStatus.Submitted;
+        return Ok(new
+        {
+            Sheet = new
+            {
+                sheet.Id,
+                sheet.ExperimentProjectId,
+                sheet.ProjectCode,
+                sheet.ProjectName,
+                sheet.ArrangementMode,
+                sheet.TeachingTaskId,
+                sheet.TaskNumber,
+                sheet.TaskName,
+                sheet.AcademicTermId,
+                sheet.TermName,
+                sheet.CourseCollegeName,
+                sheet.CourseCode,
+                sheet.CourseName,
+                sheet.TeacherNames,
+                sheet.ContributionWeight,
+                sheet.PassScore,
+                sheet.Items,
+                sheet.Status,
+                sheet.ReviewComment,
+                sheet.SubmittedAt,
+                sheet.ReviewedAt,
+                sheet.PublishedAt,
+                RecordTotal = recordTotal,
+                RecordPage = recordPage,
+                RecordPageSize = recordPageSize,
+                Records = records,
+                sheet.CreatedAt,
+                sheet.UpdatedAt
+            },
+            CanEdit = CanEdit(task) &&
+                sheet.Status is
+                    ExperimentGradeSheetStatus.Draft or
+                    ExperimentGradeSheetStatus.Returned,
+            CanReview = canReview,
+            CanPublish = IsPublisher() &&
+                sheet.Status == ExperimentGradeSheetStatus.Approved
+        });
+    }
+
+    [HttpPut("sheets/{id:guid}/settings")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> UpdateSettings(
+        Guid id,
+        ExperimentGradeSettingsRequest request,
+        CancellationToken cancellationToken)
+    {
+        var replacementItems = BuildItems(request.Items);
+        if (!ExperimentGradeCalculator.AreWeightsValid(
+                request.ContributionWeight,
+                request.PassScore,
+                replacementItems))
+            return ValidationProblem(
+                "实验评分项至少设置一项、权重合计 100%，项目贡献权重应大于 0。");
+
+        var sheet = await ScopedSheets()
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEdit(sheet.ExperimentProject!.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                ExperimentGradeSheetStatus.Draft or
+                ExperimentGradeSheetStatus.Returned))
+            return ConflictProblem("当前状态不能修改实验评分方案。");
+
+        sheet.ContributionWeight = request.ContributionWeight;
+        sheet.PassScore = request.PassScore;
+        db.ExperimentGradeItems.RemoveRange(sheet.Items);
+        foreach (var record in sheet.Records)
+        {
+            record.ItemScores.Clear();
+            record.TotalScore = null;
+            record.IsPassed = null;
+        }
+        sheet.Items = replacementItems;
+        foreach (var record in sheet.Records)
+            foreach (var item in replacementItems)
+                record.ItemScores.Add(new ExperimentGradeItemScore
+                {
+                    ExperimentGradeItemId = item.Id
+                });
+        await db.SaveChangesAsync(cancellationToken);
+        return NoContent();
+    }
+
+    [HttpPut("sheets/{id:guid}/records")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> UpdateRecords(
+        Guid id,
+        ExperimentGradeRecordsRequest request,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await ScopedSheets()
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEdit(sheet.ExperimentProject!.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                ExperimentGradeSheetStatus.Draft or
+                ExperimentGradeSheetStatus.Returned))
+            return ConflictProblem("成绩单提交后不能继续修改。");
+
+        var records = sheet.Records.ToDictionary(x => x.Id);
+        if (request.Records.Select(x => x.Id).Distinct().Count() !=
+                request.Records.Count ||
+            request.Records.Any(x => !records.ContainsKey(x.Id)))
+            return ValidationProblem("包含无效或重复的实验成绩记录。");
+        var itemIds = sheet.Items.Select(x => x.Id).ToHashSet();
+        foreach (var item in request.Records)
+        {
+            if (item.AttemptNumber is < 1 or > 20)
+                return ValidationProblem("实验尝试次数应在 1—20 次之间。");
+            if (item.ItemScores.Select(x => x.ExperimentGradeItemId)
+                    .Distinct().Count() != item.ItemScores.Count ||
+                item.ItemScores.Any(x =>
+                    !itemIds.Contains(x.ExperimentGradeItemId) ||
+                    !ValidScore(x.Score)))
+                return ValidationProblem("包含无效、重复或超出 0—100 分的评分项。");
+
+            var record = records[item.Id];
+            record.ParticipationStatus = item.ParticipationStatus;
+            record.SafetyViolation = item.SafetyViolation;
+            record.AttemptNumber = item.AttemptNumber;
+            record.SubmissionReference =
+                Normalize(item.SubmissionReference);
+            record.SubmittedAt = item.SubmittedAt;
+            record.IsLate = item.IsLate;
+            record.TeacherComment = Normalize(item.TeacherComment);
+            var scores = record.ItemScores.ToDictionary(
+                x => x.ExperimentGradeItemId);
+            foreach (var score in item.ItemScores)
+            {
+                var target = scores[score.ExperimentGradeItemId];
+                target.Score = score.Score;
+                target.Comment = Normalize(score.Comment);
+            }
+            Recalculate(sheet, record);
+        }
+        await db.SaveChangesAsync(cancellationToken);
+        return NoContent();
+    }
+
+    [HttpPost("sheets/{id:guid}/sync-participants")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> SyncParticipants(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await ScopedSheets()
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEdit(sheet.ExperimentProject!.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                ExperimentGradeSheetStatus.Draft or
+                ExperimentGradeSheetStatus.Returned))
+            return ConflictProblem("成绩单提交后不能同步参与学生。");
+
+        var expected = await LoadParticipantsAsync(
+            sheet.ExperimentProject,
+            cancellationToken);
+        var expectedByStudent = expected.ToDictionary(x => x.StudentId);
+        var existingByStudent = sheet.Records.ToDictionary(x => x.StudentId);
+        var added = 0;
+        var removed = 0;
+        var retained = 0;
+        var recordsToRemove = new List<ExperimentGradeRecord>();
+        var recordsToAdd = new List<ExperimentGradeRecord>();
+
+        foreach (var participant in expected)
+        {
+            if (existingByStudent.TryGetValue(
+                    participant.StudentId,
+                    out var record))
+            {
+                if (record.ParticipationStatus ==
+                        ExperimentParticipationStatus.Pending &&
+                    record.ItemScores.All(x => !x.Score.HasValue))
+                    record.ExperimentSessionId = participant.SessionId;
+                retained++;
+                continue;
+            }
+
+            var newRecord = new ExperimentGradeRecord
+            {
+                ExperimentGradeSheetId = sheet.Id,
+                StudentId = participant.StudentId,
+                ExperimentSessionId = participant.SessionId
+            };
+            db.ExperimentGradeRecords.Add(newRecord);
+            recordsToAdd.Add(newRecord);
+            added++;
+        }
+
+        foreach (var record in sheet.Records
+                     .Where(x => !expectedByStudent.ContainsKey(x.StudentId))
+                     .ToList())
+        {
+            if (record.ParticipationStatus !=
+                    ExperimentParticipationStatus.Pending ||
+                record.ItemScores.Any(x => x.Score.HasValue))
+            {
+                retained++;
+                continue;
+            }
+
+            db.ExperimentGradeItemScores.RemoveRange(record.ItemScores);
+            recordsToRemove.Add(record);
+            removed++;
+        }
+
+        if (recordsToRemove.Count > 0 || recordsToAdd.Count > 0)
+        {
+            await db.SaveChangesAsync(cancellationToken);
+            foreach (var record in recordsToRemove)
+                sheet.Records.Remove(record);
+            db.ExperimentGradeRecords.RemoveRange(recordsToRemove);
+        }
+        foreach (var record in recordsToAdd)
+            foreach (var item in sheet.Items)
+                record.ItemScores.Add(new ExperimentGradeItemScore
+                {
+                    ExperimentGradeItemId = item.Id
+                });
+        await db.SaveChangesAsync(cancellationToken);
+        return Ok(new
+        {
+            Added = added,
+            Removed = removed,
+            Retained = retained,
+            Total = await db.ExperimentGradeRecords.CountAsync(
+                x => x.ExperimentGradeSheetId == sheet.Id,
+                cancellationToken)
+        });
+    }
+
+    [HttpPost("sheets/{id:guid}/submit")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> Submit(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await LoadForWorkflowAsync(id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEdit(sheet.ExperimentProject!.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                ExperimentGradeSheetStatus.Draft or
+                ExperimentGradeSheetStatus.Returned))
+            return ConflictProblem("只有草稿或已退回实验成绩单可以提交。");
+        if (sheet.Records.Count == 0)
+            return ConflictProblem("实验成绩单没有学生记录。");
+
+        foreach (var record in sheet.Records) Recalculate(sheet, record);
+        if (sheet.Records.Any(x =>
+                x.ParticipationStatus ==
+                    ExperimentParticipationStatus.Pending))
+            return ConflictProblem("仍有学生未登记实验参与状态。");
+        if (sheet.Records.Any(x =>
+                x.ParticipationStatus is
+                    ExperimentParticipationStatus.Completed or
+                    ExperimentParticipationStatus.Makeup &&
+                !x.TotalScore.HasValue))
+            return ConflictProblem("仍有已完成或补做学生缺少必填评分项。");
+
+        sheet.Status = ExperimentGradeSheetStatus.Submitted;
+        sheet.SubmittedAt = DateTime.UtcNow;
+        sheet.ReviewComment = null;
+        await db.SaveChangesAsync(cancellationToken);
+        await NotificationService.SendToRoleAsync(
+            db,
+            SystemRoles.CollegeAdmin,
+            "实验成绩待审核",
+            $"“{sheet.ExperimentProject!.Name}”实验成绩已提交，请及时审核。",
+            sheet.ExperimentProject.TeachingTask!.Course!.CollegeId,
+            "/experiment-grades",
+            cancellationToken,
+            NotificationCategory.Grade);
+        return NoContent();
+    }
+
+    [HttpPost("sheets/{id:guid}/approve")]
+    [Authorize(Roles = Reviewers)]
+    public async Task<ActionResult> Approve(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await LoadForWorkflowAsync(id, cancellationToken);
+        if (sheet is null) return NotFound();
+        var collegeId = sheet.ExperimentProject!.TeachingTask!.Course!.CollegeId;
+        if (!CanReviewCollege(collegeId)) return Forbid();
+        if (sheet.Status != ExperimentGradeSheetStatus.Submitted)
+            return ConflictProblem("只有待审核实验成绩单可以通过审核。");
+
+        sheet.Status = ExperimentGradeSheetStatus.Approved;
+        sheet.ReviewedAt = DateTime.UtcNow;
+        sheet.ReviewComment = null;
+        await db.SaveChangesAsync(cancellationToken);
+        await NotifyTeachersAsync(
+            sheet.ExperimentProject.TeachingTaskId,
+            "实验成绩审核通过",
+            $"“{sheet.ExperimentProject.Name}”实验成绩已通过学院审核。",
+            cancellationToken);
+        return NoContent();
+    }
+
+    [HttpPost("sheets/{id:guid}/return")]
+    [Authorize(Roles = Reviewers)]
+    public async Task<ActionResult> Return(
+        Guid id,
+        ExperimentGradeReviewRequest request,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await LoadForWorkflowAsync(id, cancellationToken);
+        if (sheet is null) return NotFound();
+        var collegeId = sheet.ExperimentProject!.TeachingTask!.Course!.CollegeId;
+        if (!CanReviewCollege(collegeId)) return Forbid();
+        if (sheet.Status != ExperimentGradeSheetStatus.Submitted)
+            return ConflictProblem("只有待审核实验成绩单可以退回。");
+        if (string.IsNullOrWhiteSpace(request.Comment))
+            return ValidationProblem("退回时必须填写修改意见。");
+
+        sheet.Status = ExperimentGradeSheetStatus.Returned;
+        sheet.ReviewedAt = DateTime.UtcNow;
+        sheet.ReviewComment = request.Comment.Trim();
+        await db.SaveChangesAsync(cancellationToken);
+        await NotifyTeachersAsync(
+            sheet.ExperimentProject.TeachingTaskId,
+            "实验成绩被退回",
+            $"“{sheet.ExperimentProject.Name}”实验成绩被退回：{sheet.ReviewComment}",
+            cancellationToken);
+        return NoContent();
+    }
+
+    [HttpPost("sheets/{id:guid}/publish")]
+    [Authorize(Roles = Publishers)]
+    public async Task<ActionResult> Publish(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await LoadForWorkflowAsync(id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!IsPublisher()) return Forbid();
+        if (sheet.Status != ExperimentGradeSheetStatus.Approved)
+            return ConflictProblem("只有审核通过的实验成绩单可以发布。");
+
+        sheet.Status = ExperimentGradeSheetStatus.Published;
+        sheet.PublishedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(cancellationToken);
+        var userIds = await db.ExperimentGradeRecords
+            .Where(x => x.ExperimentGradeSheetId == sheet.Id)
+            .Select(x => x.Student!.UserId)
+            .Where(x => x != null)
+            .Select(x => x!.Value)
+            .Distinct()
+            .ToListAsync(cancellationToken);
+        await NotificationService.SendToUserIdsAsync(
+            db,
+            userIds,
+            "实验成绩已发布",
+            $"“{sheet.ExperimentProject!.Name}”实验成绩已发布。",
+            "/experiment-grades",
+            cancellationToken,
+            NotificationCategory.Grade);
+        return NoContent();
+    }
+
+    private async Task<ExperimentGradeSheet?> LoadForWorkflowAsync(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        if (!await ScopedSheets().AnyAsync(
+                x => x.Id == id,
+                cancellationToken))
+            return null;
+        return await db.ExperimentGradeSheets
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.ExperimentProject)
+            .ThenInclude(x => x!.TeachingTask)
+            .ThenInclude(x => x!.Course)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+    }
+
+    private async Task<List<ExperimentParticipantSeed>> LoadParticipantsAsync(
+        ExperimentProject project,
+        CancellationToken cancellationToken)
+    {
+        if (project.ArrangementMode ==
+            ExperimentArrangementMode.Centralized)
+        {
+            return await TeachingTaskRosterQuery
+                .ForTask(db, project.TeachingTaskId)
+                .AsNoTracking()
+                .OrderBy(x => x.StudentNumber)
+                .Select(x => new ExperimentParticipantSeed(x.Id, null))
+                .ToListAsync(cancellationToken);
+        }
+
+        return await db.ExperimentBookings.AsNoTracking()
+            .Where(x =>
+                x.ExperimentProjectId == project.Id &&
+                x.Status == ExperimentBookingStatus.Booked &&
+                x.Student!.Status == StudentStatus.Active)
+            .OrderBy(x => x.Student!.StudentNumber)
+            .Select(x => new ExperimentParticipantSeed(
+                x.StudentId,
+                x.ExperimentSessionId))
+            .ToListAsync(cancellationToken);
+    }
+
+    private static List<ExperimentGradeItem> BuildItems(
+        IReadOnlyCollection<ExperimentGradeItemRequest>? requests) =>
+        requests?.Select((item, index) => new ExperimentGradeItem
+        {
+            Name = item.Name.Trim(),
+            Kind = item.Kind,
+            Weight = item.Weight,
+            SortOrder = index
+        }).ToList() ?? [];
+
+    private static void Recalculate(
+        ExperimentGradeSheet sheet,
+        ExperimentGradeRecord record)
+    {
+        record.TotalScore = ExperimentGradeCalculator.CalculateTotal(
+            record,
+            sheet.Items.ToList());
+        record.IsPassed = record.TotalScore.HasValue
+            ? record.TotalScore.Value >= sheet.PassScore &&
+              !record.SafetyViolation
+            : null;
+    }
+
+    private IQueryable<TeachingTask> AccessibleTeachingTasks()
+    {
+        var source = db.TeachingTasks.AsQueryable();
+        var scope = currentUserDataScope.Current;
+        if (scope.Scope == DataScope.All) return source;
+        if (scope.Scope == DataScope.College)
+            return source.Where(x =>
+                x.Course!.CollegeId == scope.RestrictedCollegeId);
+        if (scope.IsInRole(SystemRoles.Teacher))
+            return source.Where(x => x.Teachers.Any(item =>
+                item.Teacher!.UserId == scope.UserId));
+        return source.Where(_ => false);
+    }
+
+    private IQueryable<ExperimentProject> ScopedProjects()
+    {
+        var taskIds = AccessibleTeachingTasks().Select(x => x.Id);
+        return db.ExperimentProjects.Where(x =>
+            taskIds.Contains(x.TeachingTaskId));
+    }
+
+    private IQueryable<ExperimentGradeSheet> ScopedSheets()
+    {
+        var projectIds = ScopedProjects().Select(x => x.Id);
+        return db.ExperimentGradeSheets.Where(x =>
+            projectIds.Contains(x.ExperimentProjectId));
+    }
+
+    private bool CanInitialize(TeachingTask task) =>
+        currentUserDataScope.Current.IsInRole(SystemRoles.SuperAdmin) ||
+        currentUserDataScope.Current.IsInRole(SystemRoles.AcademicAdmin) ||
+        currentUserDataScope.Current.IsInRole(SystemRoles.CollegeAdmin) ||
+        IsAssignedTeacher(task);
+
+    private bool CanEdit(TeachingTask task) =>
+        currentUserDataScope.Current.IsInRole(SystemRoles.SuperAdmin) ||
+        IsAssignedTeacher(task);
+
+    private bool IsAssignedTeacher(TeachingTask task) =>
+        task.Teachers.Any(x =>
+            x.Teacher?.UserId == currentUserDataScope.Current.UserId);
+
+    private bool CanReviewCollege(Guid collegeId)
+    {
+        var scope = currentUserDataScope.Current;
+        if (!scope.IsInRole(SystemRoles.SuperAdmin) &&
+            !scope.IsInRole(SystemRoles.AcademicAdmin) &&
+            !scope.IsInRole(SystemRoles.CollegeAdmin))
+            return false;
+        return scope.Scope == DataScope.All ||
+               scope.RestrictedCollegeId == collegeId;
+    }
+
+    private bool IsPublisher() =>
+        currentUserDataScope.Current.IsInRole(SystemRoles.SuperAdmin) ||
+        currentUserDataScope.Current.IsInRole(SystemRoles.AcademicAdmin);
+
+    private Task<Student?> CurrentStudentAsync(
+        CancellationToken cancellationToken) =>
+        db.Students.FirstOrDefaultAsync(x =>
+            x.UserId == currentUserDataScope.Current.UserId &&
+            x.Status == StudentStatus.Active,
+            cancellationToken);
+
+    private async Task NotifyTeachersAsync(
+        Guid teachingTaskId,
+        string title,
+        string content,
+        CancellationToken cancellationToken)
+    {
+        var userIds = await db.TeachingTaskTeachers
+            .Where(x => x.TeachingTaskId == teachingTaskId)
+            .Select(x => x.Teacher!.UserId)
+            .Where(x => x != null)
+            .Select(x => x!.Value)
+            .Distinct()
+            .ToListAsync(cancellationToken);
+        await NotificationService.SendToUserIdsAsync(
+            db,
+            userIds,
+            title,
+            content,
+            "/experiment-grades",
+            cancellationToken,
+            NotificationCategory.Grade);
+    }
+
+    private static bool ValidScore(decimal? score) =>
+        !score.HasValue || score.Value is >= 0 and <= 100;
+
+    private static string? Normalize(string? value) =>
+        string.IsNullOrWhiteSpace(value) ? null : value.Trim();
+
+    private ActionResult ConflictProblem(string detail) =>
+        Conflict(new ProblemDetails
+        {
+            Title = "无法完成实验成绩操作",
+            Detail = detail,
+            Status = StatusCodes.Status409Conflict
+        });
+
+    private sealed record ExperimentParticipantSeed(
+        Guid StudentId,
+        Guid? SessionId);
+}
+
+public sealed record ExperimentGradeSheetRequest(
+    Guid ExperimentProjectId,
+    [Range(typeof(decimal), "0.1", "100")] decimal ContributionWeight,
+    [Range(typeof(decimal), "0", "100")] decimal PassScore,
+    IReadOnlyCollection<ExperimentGradeItemRequest> Items);
+
+public sealed record ExperimentGradeSettingsRequest(
+    [Range(typeof(decimal), "0.1", "100")] decimal ContributionWeight,
+    [Range(typeof(decimal), "0", "100")] decimal PassScore,
+    IReadOnlyCollection<ExperimentGradeItemRequest> Items);
+
+public sealed record ExperimentGradeItemRequest(
+    [Required, MaxLength(60)] string Name,
+    ExperimentGradeItemKind Kind,
+    [Range(typeof(decimal), "0.1", "100")] decimal Weight);
+
+public sealed record ExperimentGradeRecordsRequest(
+    IReadOnlyCollection<ExperimentGradeRecordRequest> Records);
+
+public sealed record ExperimentGradeRecordRequest(
+    Guid Id,
+    ExperimentParticipationStatus ParticipationStatus,
+    bool SafetyViolation,
+    [Range(1, 20)] int AttemptNumber,
+    [MaxLength(500)] string? SubmissionReference,
+    DateTime? SubmittedAt,
+    bool IsLate,
+    [MaxLength(500)] string? TeacherComment,
+    IReadOnlyCollection<ExperimentGradeItemScoreRequest> ItemScores);
+
+public sealed record ExperimentGradeItemScoreRequest(
+    Guid ExperimentGradeItemId,
+    decimal? Score,
+    [MaxLength(300)] string? Comment);
+
+public sealed record ExperimentGradeReviewRequest(
+    [MaxLength(500)] string? Comment);

src/Jiaowu.Api/Controllers/GradesController.cs

@@ -1,11 +1,13 @@
 using System.ComponentModel.DataAnnotations;
 using System.Globalization;
+using Jiaowu.Api.Contracts;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Grades;
 using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -40,18 +42,38 @@ public sealed class GradesController(
     public async Task<ActionResult> GetSheets(
         Guid? academicTermId,
         GradeSheetStatus? status,
-        CancellationToken cancellationToken)
+        string? keyword = null,
+        int page = 1,
+        int pageSize = 20,
+        CancellationToken cancellationToken = default)
     {
+        page = Math.Max(1, page);
+        pageSize = Math.Clamp(pageSize, 10, 50);
         var source = AccessibleTasks().AsNoTracking()
             .Where(x =>
                 x.Status == TeachingTaskStatus.Published ||
                 x.Status == TeachingTaskStatus.Closed);
         if (academicTermId.HasValue)
             source = source.Where(x => x.AcademicTermId == academicTermId);
+        if (status.HasValue)
+            source = source.Where(x => db.GradeSheets.Any(sheet =>
+                sheet.TeachingTaskId == x.Id && sheet.Status == status.Value));
+        if (!string.IsNullOrWhiteSpace(keyword))
+        {
+            keyword = keyword.Trim();
+            source = source.Where(x =>
+                x.TaskNumber.Contains(keyword) ||
+                x.Name.Contains(keyword) ||
+                x.Course!.Code.Contains(keyword) ||
+                x.Course.Name.Contains(keyword));
+        }
 
+        var total = await source.CountAsync(cancellationToken);
         var items = await source
             .OrderByDescending(x => x.AcademicTerm!.StartDate)
             .ThenBy(x => x.TaskNumber)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
             .Select(x => new
             {
                 x.Id,
@@ -79,7 +101,9 @@ public sealed class GradesController(
                         {
                             item.Id,
                             item.Name,
-                            item.Weight
+                            item.Weight,
+                            item.SourceType,
+                            item.SourceSnapshotAt
                         }),
                         StudentCount = sheet.Records.Count,
                         CompletedCount = sheet.Records.Count(record =>
@@ -95,10 +119,7 @@ public sealed class GradesController(
                     .FirstOrDefault()
             })
             .ToListAsync(cancellationToken);
-
+        return Ok(new PagedResult<object>(items, total, page, pageSize));
-        if (status.HasValue)
-            items = items.Where(x => x.Sheet?.Status == status.Value).ToList();
-        return Ok(items);
     }
 
     [HttpPost("sheets")]
@@ -134,15 +155,13 @@ public sealed class GradesController(
                 cancellationToken))
             return ConflictProblem("该教学班已经建立成绩单。");
 
-        var studentIds = await db.CourseEnrollments.AsNoTracking()
+        var studentIds = await TeachingTaskRosterQuery
-            .Where(x =>
+            .ForTask(db, task.Id)
-                x.Status == CourseEnrollmentStatus.Enrolled &&
+            .AsNoTracking()
-                x.CourseSelectionOffering!.TeachingTaskId == task.Id)
+            .Select(x => x.Id)
-            .Select(x => x.StudentId)
-            .Distinct()
             .ToListAsync(cancellationToken);
         if (studentIds.Count == 0)
-            return ConflictProblem("教学班当前没有有效选课学生，无法建立成绩单。");
+            return ConflictProblem("教学班当前没有有效学生，无法建立成绩单。");
 
         var sheet = new GradeSheet
         {
@@ -165,8 +184,18 @@ public sealed class GradesController(
 
     [HttpGet("sheets/{id:guid}")]
     [Authorize(Roles = SheetUsers)]
-    public async Task<ActionResult> GetSheet(Guid id, CancellationToken cancellationToken)
+    public async Task<ActionResult> GetSheet(
+        Guid id,
+        int recordPage = 1,
+        int recordPageSize = 50,
+        string? studentKeyword = null,
+        CancellationToken cancellationToken = default)
     {
+        recordPage = Math.Max(1, recordPage);
+        recordPageSize = Math.Clamp(recordPageSize, 10, 100);
+        studentKeyword = string.IsNullOrWhiteSpace(studentKeyword)
+            ? null
+            : studentKeyword.Trim();
         var sheet = await AccessibleSheets().AsNoTracking()
             .Where(x => x.Id == id)
             .Select(x => new
@@ -193,15 +222,33 @@ public sealed class GradesController(
                 {
                     item.Id,
                     item.Name,
-                    item.Weight
+                    item.Weight,
+                    item.SourceType,
+                    item.SourceSnapshotAt
                 }),
                 x.Status,
                 x.ReviewComment,
                 x.SubmittedAt,
                 x.ReviewedAt,
                 x.PublishedAt,
-                Records = x.Records
+                x.CreatedAt,
+                x.UpdatedAt
+            })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (sheet is null) return NotFound();
+
+        var recordsSource = db.GradeRecords.AsNoTracking()
+            .Where(record => record.GradeSheetId == id);
+        if (studentKeyword is not null)
+            recordsSource = recordsSource.Where(record =>
+                record.Student!.StudentNumber.Contains(studentKeyword) ||
+                record.Student.Name.Contains(studentKeyword) ||
+                record.Student.AdministrativeClass!.Name.Contains(studentKeyword));
+        var recordTotal = await recordsSource.CountAsync(cancellationToken);
+        var records = await recordsSource
             .OrderBy(record => record.Student!.StudentNumber)
+            .Skip((recordPage - 1) * recordPageSize)
+            .Take(recordPageSize)
             .Select(record => new
             {
                 record.Id,
@@ -224,12 +271,8 @@ public sealed class GradesController(
                 record.ExamStatus,
                 record.Notes,
                 record.UpdatedAt
-                    }),
-                x.CreatedAt,
-                x.UpdatedAt
             })
-            .FirstOrDefaultAsync(cancellationToken);
+            .ToListAsync(cancellationToken);
-        if (sheet is null) return NotFound();
 
         var task = await db.TeachingTasks.AsNoTracking()
             .Include(x => x.Teachers)
@@ -244,7 +287,36 @@ public sealed class GradesController(
 
         return Ok(new
         {
-            Sheet = sheet,
+            Sheet = new
+            {
+                sheet.Id,
+                sheet.TeachingTaskId,
+                sheet.TaskNumber,
+                sheet.TaskName,
+                sheet.AcademicTermId,
+                sheet.TermName,
+                sheet.CourseCode,
+                sheet.CourseName,
+                sheet.CourseCollegeId,
+                sheet.CourseCollegeName,
+                sheet.Credits,
+                sheet.TeacherNames,
+                sheet.ClassNames,
+                sheet.RegularWeight,
+                sheet.FinalWeight,
+                sheet.Items,
+                sheet.Status,
+                sheet.ReviewComment,
+                sheet.SubmittedAt,
+                sheet.ReviewedAt,
+                sheet.PublishedAt,
+                RecordTotal = recordTotal,
+                RecordPage = recordPage,
+                RecordPageSize = recordPageSize,
+                Records = records,
+                sheet.CreatedAt,
+                sheet.UpdatedAt
+            },
             CanEdit = CanEditScores(task) &&
                 sheet.Status is GradeSheetStatus.Draft or GradeSheetStatus.Returned,
             CanReview = isCourseCollegeReviewer && sheet.Status == GradeSheetStatus.Submitted,
@@ -340,7 +412,7 @@ public sealed class GradesController(
             request.Records.Any(x => !records.ContainsKey(x.Id)))
             return ValidationProblem("包含无效或重复的成绩记录。");
 
-        var itemIds = sheet.Items.Select(item => item.Id).ToHashSet();
+        var itemsById = sheet.Items.ToDictionary(item => item.Id);
         foreach (var item in request.Records)
         {
             if (!ValidScore(item.RegularScore) ||
@@ -360,7 +432,18 @@ public sealed class GradesController(
                 {
                     if (!ValidScore(scoreEntry.Score))
                         return ValidationProblem("分项成绩必须在 0—100 分之间。");
-                    if (scoreMap.TryGetValue(scoreEntry.GradeItemId, out var existing))
+                    if (!itemsById.TryGetValue(
+                            scoreEntry.GradeItemId,
+                            out var gradeItem) ||
+                        !scoreMap.TryGetValue(
+                            scoreEntry.GradeItemId,
+                            out var existing))
+                        continue;
+                    if (gradeItem.SourceType ==
+                            GradeItemSourceType.ExperimentSummary &&
+                        existing.Score != scoreEntry.Score)
+                        return ConflictProblem(
+                            $"“{gradeItem.Name}”来自实验成绩快照，不能手工修改；请重新导入实验成绩。");
                     existing.Score = scoreEntry.Score;
                 }
             }
@@ -370,6 +453,66 @@ public sealed class GradesController(
         return await SaveAsync(id, false, cancellationToken);
     }
 
+    [HttpPost("sheets/{id:guid}/import-experiment-scores")]
+    [Authorize(Roles = SheetUsers)]
+    public async Task<ActionResult> ImportExperimentScores(
+        Guid id,
+        ImportExperimentScoresRequest request,
+        CancellationToken cancellationToken)
+    {
+        var sheet = await AccessibleSheets()
+            .Include(x => x.Items)
+            .Include(x => x.Records)
+            .ThenInclude(x => x.ItemScores)
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Teachers)
+            .ThenInclude(x => x.Teacher)
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (sheet is null) return NotFound();
+        if (!CanEditScores(sheet.TeachingTask!)) return Forbid();
+        if (sheet.Status is not (
+                GradeSheetStatus.Draft or
+                GradeSheetStatus.Returned))
+            return ConflictProblem("成绩单提交后不能导入实验成绩。");
+
+        var targetItem = sheet.Items.FirstOrDefault(x =>
+            x.Id == request.GradeItemId);
+        if (targetItem is null)
+            return ValidationProblem("请选择当前成绩单中的有效分项。");
+
+        var aggregate = await ExperimentGradeAggregationService.CalculateAsync(
+            db,
+            sheet.TeachingTaskId,
+            sheet.Records.Select(x => x.StudentId).ToArray(),
+            cancellationToken);
+        if (aggregate.PublishedProjectCount == 0)
+            return ConflictProblem(
+                "该教学任务尚无已发布的实验项目成绩，无法导入。");
+
+        var imported = 0;
+        var missing = 0;
+        foreach (var record in sheet.Records)
+        {
+            var targetScore = record.ItemScores.First(x =>
+                x.GradeItemId == targetItem.Id);
+            targetScore.Score = aggregate.Scores[record.StudentId];
+            if (targetScore.Score.HasValue) imported++;
+            else missing++;
+            Recalculate(sheet, record);
+        }
+        targetItem.SourceType = GradeItemSourceType.ExperimentSummary;
+        targetItem.SourceSnapshotAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(cancellationToken);
+        return Ok(new
+        {
+            aggregate.PublishedProjectCount,
+            aggregate.Projects,
+            ImportedCount = imported,
+            MissingCount = missing,
+            targetItem.SourceSnapshotAt
+        });
+    }
+
     [HttpPost("sheets/{id:guid}/submit")]
     [Authorize(Roles = SheetUsers)]
     public async Task<ActionResult> Submit(Guid id, CancellationToken cancellationToken)
@@ -411,7 +554,8 @@ public sealed class GradesController(
             $"《{courseName}》成绩已提交，请及时审核。",
             collegeId,
             "/grades",
-            cancellationToken);
+            cancellationToken,
+            NotificationCategory.Grade);
         return NoContent();
     }
 
@@ -452,7 +596,7 @@ public sealed class GradesController(
         await NotificationService.SendToUserIdsAsync(db, teacherUserIds,
             "成绩审核通过",
             $"《{sheet.TeachingTask!.Course!.Name}》成绩已通过学院审核，等待校级发布。",
-            "/grades", cancellationToken);
+            "/grades", cancellationToken, NotificationCategory.Grade);
         return NoContent();
     }
 
@@ -497,7 +641,7 @@ public sealed class GradesController(
         await NotificationService.SendToUserIdsAsync(db, teacherUserIds,
             "成绩被退回",
             $"《{sheet.TeachingTask!.Course!.Name}》成绩被退回修改：{sheet.ReviewComment}",
-            "/grades", cancellationToken);
+            "/grades", cancellationToken, NotificationCategory.Grade);
         return NoContent();
     }
 
@@ -505,7 +649,10 @@ public sealed class GradesController(
     [Authorize(Roles = Publishers)]
     public async Task<ActionResult> Publish(Guid id, CancellationToken cancellationToken)
     {
-        var sheet = await AccessibleSheets().FirstOrDefaultAsync(
+        var sheet = await AccessibleSheets()
+            .Include(x => x.TeachingTask)
+            .ThenInclude(x => x!.Course)
+            .FirstOrDefaultAsync(
             x => x.Id == id,
             cancellationToken);
         if (sheet is null) return NotFound();
@@ -514,13 +661,11 @@ public sealed class GradesController(
             return ConflictProblem("只有审核通过的成绩单可以发布。");
         sheet.Status = GradeSheetStatus.Published;
         sheet.PublishedAt = DateTime.UtcNow;
-        await db.SaveChangesAsync(cancellationToken);
 
-        // Notify enrolled students
+        // The grade sheet roster is authoritative at publication time. This also
-        var studentUserIds = await db.CourseEnrollments
+        // covers students added through approved roster corrections.
-            .Where(x =>
+        var studentUserIds = await db.GradeRecords
-                x.CourseSelectionOffering!.TeachingTaskId == sheet.TeachingTaskId &&
+            .Where(x => x.GradeSheetId == sheet.Id)
-                x.Status == CourseEnrollmentStatus.Enrolled)
             .Select(x => x.Student!.UserId)
             .Where(id => id != null)
             .Select(id => id!.Value)
@@ -528,8 +673,8 @@ public sealed class GradesController(
             .ToListAsync(cancellationToken);
         await NotificationService.SendToUserIdsAsync(db, studentUserIds,
             "成绩已发布",
-            $"《{sheet.TeachingTask!.Course!.Name}》成绩已发布，请查看。",
+            $"《{sheet.TeachingTask!.Course!.Name}》成绩已正式发布，请前往成绩单查看。",
-            "/grades", cancellationToken);
+            "/grades", cancellationToken, NotificationCategory.Grade);
         return NoContent();
     }
 
@@ -928,5 +1073,7 @@ public sealed record GradeItemScoreRequest(
     Guid GradeItemId,
     decimal? Score);
 
+public sealed record ImportExperimentScoresRequest(Guid GradeItemId);
+
 public sealed record GradeReviewRequest(
     [MaxLength(500)] string? Comment);

src/Jiaowu.Api/Controllers/GraduationAuditsController.cs

@@ -61,8 +61,16 @@ public sealed class GraduationAuditsController(
 
     [HttpGet("batches/{id:guid}")]
     [Authorize(Roles = Reviewers)]
-    public async Task<ActionResult> GetBatch(Guid id, CancellationToken token)
+    public async Task<ActionResult> GetBatch(
+        Guid id,
+        [FromQuery] int page = 1,
+        [FromQuery] int pageSize = 20,
+        [FromQuery] string? keyword = null,
+        [FromQuery] GraduationAuditConclusion? conclusion = null,
+        CancellationToken token = default)
     {
+        page = Math.Max(page, 1);
+        pageSize = Math.Clamp(pageSize, 10, 100);
         var batch = await db.GraduationAuditBatches.AsNoTracking()
             .FirstOrDefaultAsync(x => x.Id == id, token);
         if (batch is null) return NotFound();
@@ -73,18 +81,35 @@ public sealed class GraduationAuditsController(
         if (collegeId.HasValue)
             results = results.Where(x =>
                 x.Student!.AdministrativeClass!.Major!.CollegeId == collegeId);
-        return Ok(new
+
+        var summary = await results
+            .GroupBy(_ => 1)
+            .Select(group => new
             {
-            batch.Id,
+                ResultCount = group.Count(),
-            batch.Name,
+                EligibleCount = group.Count(x =>
-            batch.GraduationYear,
+                    x.Conclusion == GraduationAuditConclusion.Eligible),
-            batch.EnrollmentYear,
+                IneligibleCount = group.Count(x =>
-            batch.Status,
+                    x.Conclusion == GraduationAuditConclusion.Ineligible),
-            batch.Notes,
+                OverrideCount = group.Count(x => x.IsOverridden)
-            batch.CalculatedAt,
+            })
-            batch.PublishedAt,
+            .FirstOrDefaultAsync(token);
-            Results = await results
+
+        var normalizedKeyword = keyword?.Trim();
+        if (!string.IsNullOrWhiteSpace(normalizedKeyword))
+            results = results.Where(x =>
+                x.Student!.StudentNumber.Contains(normalizedKeyword) ||
+                x.Student.Name.Contains(normalizedKeyword) ||
+                x.Student.AdministrativeClass!.Name.Contains(normalizedKeyword) ||
+                x.Student.AdministrativeClass.Major!.Name.Contains(normalizedKeyword));
+        if (conclusion.HasValue)
+            results = results.Where(x => x.Conclusion == conclusion.Value);
+
+        var total = await results.CountAsync(token);
+        var items = await results
             .OrderBy(x => x.Student!.StudentNumber)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
             .Select(x => new
             {
                 x.Id,
@@ -107,7 +132,29 @@ public sealed class GraduationAuditsController(
                 x.IsOverridden,
                 x.ReviewComment,
                 x.ReviewedAt
-                }).ToListAsync(token)
+            }).ToListAsync(token);
+
+        return Ok(new
+        {
+            batch.Id,
+            batch.Name,
+            batch.GraduationYear,
+            batch.EnrollmentYear,
+            batch.Status,
+            batch.Notes,
+            batch.CalculatedAt,
+            batch.PublishedAt,
+            ResultCount = summary?.ResultCount ?? 0,
+            EligibleCount = summary?.EligibleCount ?? 0,
+            IneligibleCount = summary?.IneligibleCount ?? 0,
+            OverrideCount = summary?.OverrideCount ?? 0,
+            Results = new
+            {
+                Items = items,
+                Total = total,
+                Page = page,
+                PageSize = pageSize
+            }
         });
     }
 
@@ -156,10 +203,11 @@ public sealed class GraduationAuditsController(
             .Where(x => x.EffectiveGrade == batch.EnrollmentYear &&
                         x.Status == CurriculumPlanStatus.Published)
             .ToListAsync(token);
-        var studentIds = students.Select(x => x.Id).ToArray();
         var grades = await db.GradeRecords.AsNoTracking()
             .Where(x => x.GradeSheet!.Status == GradeSheetStatus.Published)
-            .WhereIn(studentIds, x => x.StudentId)
+            .Where(x => x.Student!.EnrollmentYear == batch.EnrollmentYear &&
+                        (x.Student.Status == StudentStatus.Active ||
+                         x.Student.Status == StudentStatus.Suspended))
             .Select(x => new GradeSnapshot(
                 x.StudentId,
                 x.GradeSheet!.TeachingTask!.CourseId,
@@ -169,16 +217,23 @@ public sealed class GraduationAuditsController(
                 x.ExamStatus))
             .ToListAsync(token);
 
-        var oldResults = await db.GraduationAuditResults
+        var plansByMajor = plans
-            .Where(x => x.GraduationAuditBatchId == id).ToListAsync(token);
+            .GroupBy(x => x.MajorId)
-        db.GraduationAuditResults.RemoveRange(oldResults);
+            .ToDictionary(group => group.Key, group => group.First());
-        await db.SaveChangesAsync(token);
+        var gradesByStudent = grades
+            .GroupBy(x => x.StudentId)
+            .ToDictionary(group => group.Key, group => group.ToList());
+
+        await db.GraduationAuditResults
+            .Where(x => x.GraduationAuditBatchId == id)
+            .ExecuteDeleteAsync(token);
 
         foreach (var student in students)
         {
-            var plan = plans.FirstOrDefault(x =>
+            plansByMajor.TryGetValue(
-                x.MajorId == student.AdministrativeClass!.MajorId);
+                student.AdministrativeClass!.MajorId,
-            var studentGrades = grades.Where(x => x.StudentId == student.Id).ToList();
+                out var plan);
+            var studentGrades = gradesByStudent.GetValueOrDefault(student.Id) ?? [];
             var passedCourseIds = studentGrades
                 .Where(IsPassed)
                 .Select(x => x.CourseId)

src/Jiaowu.Api/Controllers/GraduationClearanceController.cs

@@ -34,31 +34,46 @@ public sealed class GraduationClearanceController(
                 x.Id, x.Name, x.GraduationYear, x.Status, x.Notes,
                 x.ClosedAt, x.CreatedAt, ItemCount = x.Items.Count
             }).ToListAsync(token);
-        var records = await ScopedRecords().AsNoTracking()
+        var statistics = await ScopedRecords().AsNoTracking()
-            .Select(x => new
+            .GroupBy(x => x.GraduationClearanceItem!.GraduationClearanceBatchId)
+            .Select(group => new
             {
-                BatchId = x.GraduationClearanceItem!.GraduationClearanceBatchId,
+                BatchId = group.Key,
-                x.StudentId, x.Status
+                StudentCount = group.Select(x => x.StudentId).Distinct().Count(),
-            }).ToListAsync(token);
+                RecordCount = group.Count(),
+                CompletedCount = group.Count(x =>
+                    x.Status != GraduationClearanceRecordStatus.Pending)
+            }).ToDictionaryAsync(x => x.BatchId, token);
         return Ok(batches.Select(batch =>
         {
-            var scoped = records.Where(x => x.BatchId == batch.Id).ToList();
+            statistics.TryGetValue(batch.Id, out var summary);
             return new
             {
                 batch.Id, batch.Name, batch.GraduationYear, batch.Status,
                 batch.Notes, batch.ClosedAt, batch.CreatedAt, batch.ItemCount,
-                StudentCount = scoped.Select(x => x.StudentId).Distinct().Count(),
+                StudentCount = summary?.StudentCount ?? 0,
-                RecordCount = scoped.Count,
+                RecordCount = summary?.RecordCount ?? 0,
-                CompletedCount = scoped.Count(x =>
+                CompletedCount = summary?.CompletedCount ?? 0
-                    x.Status != GraduationClearanceRecordStatus.Pending)
             };
         }));
     }
 
     [HttpGet("batches/{id:guid}")]
     [Authorize(Roles = Workers)]
-    public async Task<ActionResult> GetBatch(Guid id, CancellationToken token)
+    public async Task<ActionResult> GetBatch(
+        Guid id,
+        [FromQuery] int page = 1,
+        [FromQuery] int pageSize = 20,
+        [FromQuery] string? keyword = null,
+        [FromQuery] string? progress = null,
+        CancellationToken token = default)
     {
+        page = Math.Max(page, 1);
+        pageSize = Math.Clamp(pageSize, 10, 100);
+        var normalizedProgress = progress?.Trim();
+        if (normalizedProgress is not null and not "Pending" and not "Completed")
+            return ValidationProblem("离校办理进度筛选值无效。");
+
         var batch = await db.GraduationClearanceBatches.AsNoTracking()
             .Where(x => x.Id == id)
             .Select(x => new
@@ -72,8 +87,56 @@ public sealed class GraduationClearanceController(
                 })
             }).FirstOrDefaultAsync(token);
         if (batch is null) return NotFound();
-        var records = await ScopedRecords().AsNoTracking()
+
-            .Where(x => x.GraduationClearanceItem!.GraduationClearanceBatchId == id)
+        var records = ScopedRecords().AsNoTracking()
+            .Where(x => x.GraduationClearanceItem!.GraduationClearanceBatchId == id);
+        var summary = await records
+            .GroupBy(_ => 1)
+            .Select(group => new
+            {
+                StudentCount = group.Select(x => x.StudentId).Distinct().Count(),
+                RecordCount = group.Count(),
+                CompletedCount = group.Count(x =>
+                    x.Status != GraduationClearanceRecordStatus.Pending)
+            })
+            .FirstOrDefaultAsync(token);
+
+        var students = db.Students.AsNoTracking()
+            .Where(student => records.Any(record => record.StudentId == student.Id));
+        var normalizedKeyword = keyword?.Trim();
+        if (!string.IsNullOrWhiteSpace(normalizedKeyword))
+            students = students.Where(student =>
+                student.StudentNumber.Contains(normalizedKeyword) ||
+                student.Name.Contains(normalizedKeyword) ||
+                student.AdministrativeClass!.Name.Contains(normalizedKeyword) ||
+                student.AdministrativeClass.Major!.Name.Contains(normalizedKeyword));
+        if (normalizedProgress == "Pending")
+            students = students.Where(student => records.Any(record =>
+                record.StudentId == student.Id &&
+                record.GraduationClearanceItem!.IsRequired &&
+                record.Status == GraduationClearanceRecordStatus.Pending));
+        else if (normalizedProgress == "Completed")
+            students = students.Where(student => !records.Any(record =>
+                record.StudentId == student.Id &&
+                record.GraduationClearanceItem!.IsRequired &&
+                record.Status == GraduationClearanceRecordStatus.Pending));
+
+        var total = await students.CountAsync(token);
+        var studentPage = await students
+            .OrderBy(student => student.StudentNumber)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .Select(student => new
+            {
+                student.Id,
+                student.StudentNumber,
+                student.Name,
+                ClassName = student.AdministrativeClass!.Name,
+                MajorName = student.AdministrativeClass.Major!.Name
+            }).ToListAsync(token);
+        var studentIds = studentPage.Select(student => student.Id).ToArray();
+        var pageRecords = await records
+            .WhereIn(studentIds, x => x.StudentId)
             .OrderBy(x => x.Student!.StudentNumber)
             .ThenBy(x => x.GraduationClearanceItem!.SortOrder)
             .Select(x => new
@@ -89,11 +152,32 @@ public sealed class GraduationClearanceController(
                 x.GraduationClearanceItem.IsRequired,
                 x.Status, x.Notes, x.CompletedAt
             }).ToListAsync(token);
+        var recordsByStudent = pageRecords
+            .GroupBy(record => record.StudentId)
+            .ToDictionary(group => group.Key, group => group.ToList());
+        var studentItems = studentPage.Select(student => new
+        {
+            StudentId = student.Id,
+            student.StudentNumber,
+            student.Name,
+            student.ClassName,
+            student.MajorName,
+            Records = recordsByStudent.GetValueOrDefault(student.Id) ?? []
+        }).ToList();
         return Ok(new
         {
             batch.Id, batch.Name, batch.GraduationYear, batch.Status,
             batch.Notes, batch.ClosedAt, batch.CreatedAt, batch.Items,
-            Records = records
+            StudentCount = summary?.StudentCount ?? 0,
+            RecordCount = summary?.RecordCount ?? 0,
+            CompletedCount = summary?.CompletedCount ?? 0,
+            Students = new
+            {
+                Items = studentItems,
+                Total = total,
+                Page = page,
+                PageSize = pageSize
+            }
         });
     }
 
@@ -150,16 +234,15 @@ public sealed class GraduationClearanceController(
         if (batch.Status != GraduationClearanceBatchStatus.Open)
             return ConflictProblem("已关闭批次不能重新生成办理记录。");
 
-        var eligibleAudits = await db.GraduationAuditResults.AsNoTracking()
+        var studentIds = await db.GraduationAuditResults.AsNoTracking()
             .Where(x =>
                 x.GraduationAuditBatch!.GraduationYear == batch.GraduationYear &&
                 x.GraduationAuditBatch.Status == GraduationAuditBatchStatus.Published &&
                 x.Conclusion == GraduationAuditConclusion.Eligible &&
                 x.Student!.Status == StudentStatus.Graduated)
-            .OrderByDescending(x => x.GraduationAuditBatch!.PublishedAt)
+            .Select(x => x.StudentId)
-            .Select(x => new { x.StudentId })
+            .Distinct()
             .ToListAsync(token);
-        var studentIds = eligibleAudits.Select(x => x.StudentId).Distinct().ToArray();
         var existing = await db.GraduationClearanceRecords.AsNoTracking()
             .Where(x => x.GraduationClearanceItem!.GraduationClearanceBatchId == id)
             .Select(x => new { x.GraduationClearanceItemId, x.StudentId })
@@ -180,7 +263,7 @@ public sealed class GraduationClearanceController(
             created++;
         }
         await db.SaveChangesAsync(token);
-        return Ok(new { StudentCount = studentIds.Length, CreatedRecordCount = created });
+        return Ok(new { StudentCount = studentIds.Count, CreatedRecordCount = created });
     }
 
     [HttpPut("records/{id:guid}")]
@@ -221,15 +304,17 @@ public sealed class GraduationClearanceController(
     public async Task<ActionResult> Close(Guid id, CancellationToken token)
     {
         var batch = await db.GraduationClearanceBatches
-            .Include(x => x.Items)
-            .ThenInclude(x => x.Records)
             .FirstOrDefaultAsync(x => x.Id == id, token);
         if (batch is null) return NotFound();
         if (batch.Status != GraduationClearanceBatchStatus.Open)
             return ConflictProblem("该批次已经关闭。");
-        var records = batch.Items.SelectMany(item => item.Records.Select(record =>
+        var hasIncompleteRequiredItem = await db.GraduationClearanceRecords
-            (item.IsRequired, record.Status)));
+            .AnyAsync(record =>
-        if (!GraduationClearanceRules.CanClose(records))
+                record.GraduationClearanceItem!.GraduationClearanceBatchId == id &&
+                record.GraduationClearanceItem.IsRequired &&
+                record.Status == GraduationClearanceRecordStatus.Pending,
+                token);
+        if (hasIncompleteRequiredItem)
             return ConflictProblem("仍有必办离校事项尚未完成。");
         batch.Status = GraduationClearanceBatchStatus.Closed;
         batch.ClosedAt = DateTime.UtcNow;

src/Jiaowu.Api/Controllers/MakeupExamsController.cs

@@ -1,6 +1,7 @@
 using System.ComponentModel.DataAnnotations;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Domain.System;
 using Jiaowu.Api.Infrastructure.Auth;
 using Jiaowu.Api.Infrastructure.Exams;
 using Jiaowu.Api.Infrastructure.Grades;
@@ -17,9 +18,7 @@ namespace Jiaowu.Api.Controllers;
 public sealed class MakeupExamsController(
     AppDbContext db,
     ICurrentUserDataScope currentUserDataScope,
-    MakeupExamEligibilityService eligibilityService,
+    MakeupExamEligibilityService eligibilityService) : ControllerBase
-    MakeupExamArrangementService arrangementService,
-    MakeupExamAutoJobQueue autoJobQueue) : ControllerBase
 {
     private const string Managers =
         SystemRoles.SuperAdmin + "," + SystemRoles.AcademicAdmin;
@@ -111,6 +110,7 @@ public sealed class MakeupExamsController(
                         item.StartsAt,
                         item.EndsAt,
                         item.RequiredBuildingId,
+                        item.RequiredBuildingIds,
                         RequiredBuildingName = item.RequiredBuilding != null
                         ? item.RequiredBuilding.Name : null,
                         item.RequiredInvigilatorCount,
@@ -138,38 +138,90 @@ public sealed class MakeupExamsController(
     [Authorize(Roles = Managers)]
     public async Task<ActionResult> Publish(Guid id, CancellationToken cancellationToken)
     {
-        var plan = await db.MakeupExamPlans
+        if (await FindActiveArrangementJobAsync(id, cancellationToken) is not null)
-            .Include(x => x.Sessions)
+            return ConflictProblem("补考计划正在后台编排，完成后才能发布。");
-                .ThenInclude(x => x.Invigilators)
+        if (await FindActivePublishJobAsync(id, cancellationToken) is not null)
-            .Include(x => x.Sessions)
+            return ConflictProblem("补考计划正在后台发布，请等待任务完成。");
-                .ThenInclude(x => x.Enrollments)
+
-            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        var plan = await db.MakeupExamPlans.AsNoTracking()
+            .Where(x => x.Id == id)
+            .Select(x => new
+            {
+                x.Status,
+                HasSessions = x.Sessions.Any()
+            })
+            .FirstOrDefaultAsync(cancellationToken);
         if (plan is null) return NotFound();
         if (plan.Status != MakeupExamPlanStatus.Draft)
             return ConflictProblem("只有草稿补考计划可以发布。");
-        if (plan.Sessions.Count == 0)
+        if (!plan.HasSessions)
             return ConflictProblem("至少安排一个考试场次后才能发布。");
 
-        var unassigned = plan.Sessions.Count(x =>
+        var userId = currentUserDataScope.Current.UserId;
-            !x.ClassroomId.HasValue || x.Invigilators.Count == 0);
+        var job = new ExamPublishJob
-        if (unassigned > 0)
+        {
-            return ConflictProblem(
+            Kind = ExamPublishJobKind.MakeupExam,
-                $"还有 {unassigned} 个场次未分配考场或监考教师，请先完成自动编排。");
+            PlanId = id,
+            ActivePlanId = id,
+            RequestedByUserId = userId == Guid.Empty ? null : userId,
+            CurrentStep = "等待后台校验"
+        };
+        db.ExamPublishJobs.Add(job);
+        db.BackgroundJobOutboxMessages.Add(
+            BackgroundJobOutboxMessage.Create(
+                BackgroundJobKind.ExamPublish,
+                job.Id));
+        try
+        {
+            await db.SaveChangesAsync(cancellationToken);
+        }
+        catch (DbUpdateException)
+        {
+            db.ChangeTracker.Clear();
+            var existing = await FindActivePublishJobAsync(id, cancellationToken);
+            if (existing is not null)
+                return AcceptedPublishJob(existing, "该计划已有正在执行的发布任务。");
+            throw;
+        }
 
-        var empty = plan.Sessions.Count(x => x.Enrollments.Count == 0);
+        return AcceptedPublishJob(job, "补考发布任务已提交。");
-        if (empty > 0)
+    }
-            return ConflictProblem(
-                $"还有 {empty} 个场次没有登记补考学生。");
 
-        plan.Status = MakeupExamPlanStatus.Published;
+    [HttpGet("publish-jobs/{jobId:guid}")]
-        plan.PublishedAt = DateTime.UtcNow;
+    [Authorize(Roles = Managers)]
-        return await SaveAsync(id, false, cancellationToken);
+    public async Task<ActionResult> GetPublishJob(
+        Guid jobId,
+        CancellationToken cancellationToken)
+    {
+        var job = await db.ExamPublishJobs.AsNoTracking()
+            .FirstOrDefaultAsync(
+                x => x.Id == jobId &&
+                     x.Kind == ExamPublishJobKind.MakeupExam,
+                cancellationToken);
+        return job is null ? NotFound() : Ok(ToPublishJobResponse(job));
+    }
+
+    [HttpGet("plans/{planId:guid}/publish-job")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> GetLatestPublishJob(
+        Guid planId,
+        CancellationToken cancellationToken)
+    {
+        var job = await db.ExamPublishJobs.AsNoTracking()
+            .Where(x =>
+                x.PlanId == planId &&
+                x.Kind == ExamPublishJobKind.MakeupExam)
+            .OrderByDescending(x => x.CreatedAt)
+            .FirstOrDefaultAsync(cancellationToken);
+        return job is null ? NoContent() : Ok(ToPublishJobResponse(job));
     }
 
     [HttpPost("plans/{id:guid}/archive")]
     [Authorize(Roles = Managers)]
     public async Task<ActionResult> Archive(Guid id, CancellationToken cancellationToken)
     {
+        if (await FindActiveArrangementJobAsync(id, cancellationToken) is not null)
+            return ConflictProblem("补考计划正在后台编排，暂时不能归档。");
         var plan = await db.MakeupExamPlans.FindAsync([id], cancellationToken);
         if (plan is null) return NotFound();
         if (plan.Status != MakeupExamPlanStatus.Published)
@@ -189,6 +241,8 @@ public sealed class MakeupExamsController(
         CreateMakeupExamSessionRequest request,
         CancellationToken cancellationToken)
     {
+        if (await FindActiveArrangementJobAsync(planId, cancellationToken) is not null)
+            return ConflictProblem("补考计划正在后台编排，暂时不能调整场次。");
         var plan = await db.MakeupExamPlans.FindAsync([planId], cancellationToken);
         if (plan is null) return NotFound();
         if (plan.Status != MakeupExamPlanStatus.Draft)
@@ -215,6 +269,7 @@ public sealed class MakeupExamsController(
             StartsAt = startsAt,
             EndsAt = endsAt,
             RequiredBuildingId = request.RequiredBuildingId,
+            RequiredBuildingIds = SerializeBuildingIds(request.RequiredBuildingIds),
             RequiredInvigilatorCount = request.RequiredInvigilatorCount,
             Notes = Normalize(request.Notes),
             Invigilators = (request.InvigilatorIds ?? []).Distinct().Select(id =>
@@ -224,6 +279,81 @@ public sealed class MakeupExamsController(
         return await SaveAsync(session.Id, true, cancellationToken);
     }
 
+    [HttpPost("plans/{planId:guid}/sessions/batch")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> CreateSessionsBatch(
+        Guid planId,
+        CreateMakeupExamSessionsBatchRequest request,
+        CancellationToken cancellationToken)
+    {
+        if (await FindActiveArrangementJobAsync(planId, cancellationToken) is not null)
+            return ConflictProblem("补考计划正在后台编排，暂时不能调整场次。");
+        var plan = await db.MakeupExamPlans.FindAsync([planId], cancellationToken);
+        if (plan is null) return NotFound();
+        if (plan.Status != MakeupExamPlanStatus.Draft)
+            return ConflictProblem("已发布的补考计划不能调整场次。");
+
+        var taskIds = request.TeachingTaskIds.Distinct().ToArray();
+        if (taskIds.Length == 0)
+            return ValidationProblem("请至少选择一个教学班。");
+        if (taskIds.Length > 100)
+            return ValidationProblem("一次最多选择100个教学班。");
+
+        var timeResult = ResolveExamTime(plan.AcademicTermId,
+            request.ExamDate, request.StartPeriod, request.PeriodCount);
+        if (timeResult.Error is not null) return timeResult.Error;
+        var (startsAt, endsAt) = (timeResult.StartsAt, timeResult.EndsAt);
+
+        var validTaskIds = await db.TeachingTasks.AsNoTracking()
+            .Where(x => x.AcademicTermId == plan.AcademicTermId &&
+                        x.Status == TeachingTaskStatus.Published)
+            .WhereIn(taskIds, x => x.Id)
+            .Select(x => x.Id)
+            .ToListAsync(cancellationToken);
+        if (validTaskIds.Count != taskIds.Length)
+            return ValidationProblem("所选教学班包含不存在、跨学期或未发布的教学班。");
+
+        var duplicateTaskIds = await db.MakeupExamSessions.AsNoTracking()
+            .Where(x => x.MakeupExamPlanId == planId)
+            .WhereIn(taskIds, x => x.TeachingTaskId)
+            .Select(x => x.TeachingTaskId)
+            .ToListAsync(cancellationToken);
+        if (duplicateTaskIds.Count > 0)
+            return ConflictProblem($"所选教学班中有 {duplicateTaskIds.Count} 个已在当前补考计划中安排。");
+
+        foreach (var taskId in taskIds)
+        {
+            var validation = await ValidateSessionAsync(plan, null,
+                taskId, null, null, startsAt, endsAt, cancellationToken);
+            if (validation is not null) return validation;
+        }
+
+        db.MakeupExamSessions.AddRange(taskIds.Select(taskId => new MakeupExamSession
+        {
+            MakeupExamPlanId = planId,
+            TeachingTaskId = taskId,
+            ExamDate = request.ExamDate,
+            StartPeriod = request.StartPeriod,
+            PeriodCount = request.PeriodCount,
+            StartsAt = startsAt,
+            EndsAt = endsAt,
+            RequiredBuildingId = request.RequiredBuildingId,
+            RequiredBuildingIds = SerializeBuildingIds(request.RequiredBuildingIds),
+            RequiredInvigilatorCount = request.RequiredInvigilatorCount,
+            Notes = Normalize(request.Notes)
+        }));
+
+        try
+        {
+            await db.SaveChangesAsync(cancellationToken);
+            return Ok(new { createdCount = taskIds.Length });
+        }
+        catch (DbUpdateException)
+        {
+            return ConflictProblem("批量创建补考场次失败，关联数据可能已发生变化。");
+        }
+    }
+
     [HttpPut("plans/{planId:guid}/sessions/{id:guid}")]
     [Authorize(Roles = Managers)]
     public async Task<ActionResult> UpdateSession(
@@ -232,6 +362,8 @@ public sealed class MakeupExamsController(
         CreateMakeupExamSessionRequest request,
         CancellationToken cancellationToken)
     {
+        if (await FindActiveArrangementJobAsync(planId, cancellationToken) is not null)
+            return ConflictProblem("补考计划正在后台编排，暂时不能调整场次。");
         var session = await db.MakeupExamSessions
             .Include(x => x.MakeupExamPlan)
             .Include(x => x.Invigilators)
@@ -258,6 +390,7 @@ public sealed class MakeupExamsController(
         session.StartsAt = startsAt;
         session.EndsAt = endsAt;
         session.RequiredBuildingId = request.RequiredBuildingId;
+        session.RequiredBuildingIds = SerializeBuildingIds(request.RequiredBuildingIds);
         session.RequiredInvigilatorCount = request.RequiredInvigilatorCount;
         session.Notes = Normalize(request.Notes);
 
@@ -275,6 +408,8 @@ public sealed class MakeupExamsController(
         Guid id,
         CancellationToken cancellationToken)
     {
+        if (await FindActiveArrangementJobAsync(planId, cancellationToken) is not null)
+            return ConflictProblem("补考计划正在后台编排，暂时不能调整场次。");
         var session = await db.MakeupExamSessions.Include(x => x.MakeupExamPlan)
             .FirstOrDefaultAsync(x => x.Id == id && x.MakeupExamPlanId == planId, cancellationToken);
         if (session is null) return NotFound();
@@ -292,12 +427,121 @@ public sealed class MakeupExamsController(
     [Authorize(Roles = Managers)]
     public async Task<ActionResult> AutoArrange(
         Guid planId,
+        ExamAutoArrangeRequest? request,
         CancellationToken cancellationToken)
     {
-        var result = await arrangementService.ArrangeAsync(planId, cancellationToken);
+        request ??= new ExamAutoArrangeRequest();
-        if (!result.Success)
+        if (!request.AssignClassrooms && !request.AssignInvigilators)
-            return ConflictProblem(result.Message);
+            return ValidationProblem("请至少选择分配考场或分配监考教师。");
-        return Ok(new { message = result.Message });
+
+        var sessionIds = (request.SessionIds ?? []).Distinct().ToArray();
+        if (sessionIds.Length > 100)
+            return ValidationProblem("一次最多处理100个补考场次。");
+
+        var plan = await db.MakeupExamPlans.AsNoTracking()
+            .Where(x => x.Id == planId)
+            .Select(x => new
+            {
+                x.Status,
+                TotalSessions = x.Sessions.Count
+            })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (plan is null)
+            return NotFound();
+        if (plan.Status != MakeupExamPlanStatus.Draft)
+            return ConflictProblem("只有草稿状态的补考计划可以自动编排。");
+        if (sessionIds.Length > 0)
+        {
+            var selectedSessionCount = await db.MakeupExamSessions.AsNoTracking()
+                .Where(x => x.MakeupExamPlanId == planId)
+                .WhereIn(sessionIds, x => x.Id)
+                .CountAsync(cancellationToken);
+            if (selectedSessionCount != sessionIds.Length)
+                return ConflictProblem("所选场次不存在或不属于当前补考计划。");
+        }
+
+        var autoCreateActive = await db.MakeupExamAutoJobs.AsNoTracking()
+            .AnyAsync(
+                x => x.MakeupExamPlanId == planId &&
+                     (x.Status == MakeupExamAutoJobStatus.Queued ||
+                      x.Status == MakeupExamAutoJobStatus.Running),
+                cancellationToken);
+        if (autoCreateActive)
+            return ConflictProblem("该计划正在自动生成补考场次，请完成后再编排。");
+
+        var existing = await FindActiveArrangementJobAsync(
+            planId,
+            cancellationToken);
+        if (existing is not null)
+            return AcceptedArrangementJob(existing, "该计划已有正在执行的编排任务。");
+
+        var userId = currentUserDataScope.Current.UserId;
+        var job = new ExamArrangementJob
+        {
+            Kind = ExamArrangementKind.MakeupExam,
+            PlanId = planId,
+            ActivePlanId = planId,
+            RequestedByUserId = userId == Guid.Empty ? null : userId,
+            SessionIdsJson = sessionIds.Length == 0
+                ? null
+                : System.Text.Json.JsonSerializer.Serialize(sessionIds),
+            AssignClassrooms = request.AssignClassrooms,
+            AssignInvigilators = request.AssignInvigilators,
+            TotalSessions = sessionIds.Length == 0
+                ? plan.TotalSessions
+                : sessionIds.Length,
+            CurrentStep = "等待后台编排"
+        };
+        db.ExamArrangementJobs.Add(job);
+        db.BackgroundJobOutboxMessages.Add(
+            BackgroundJobOutboxMessage.Create(
+                BackgroundJobKind.ExamArrangement,
+                job.Id));
+        try
+        {
+            await db.SaveChangesAsync(cancellationToken);
+        }
+        catch (DbUpdateException)
+        {
+            db.ChangeTracker.Clear();
+            existing = await FindActiveArrangementJobAsync(
+                planId,
+                cancellationToken);
+            if (existing is not null)
+                return AcceptedArrangementJob(existing, "该计划已有正在执行的编排任务。");
+            throw;
+        }
+
+        return AcceptedArrangementJob(job, "补考编排任务已提交。");
+    }
+
+    [HttpGet("arrangement-jobs/{jobId:guid}")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> GetArrangementJob(
+        Guid jobId,
+        CancellationToken cancellationToken)
+    {
+        var job = await db.ExamArrangementJobs.AsNoTracking()
+            .FirstOrDefaultAsync(
+                x => x.Id == jobId &&
+                     x.Kind == ExamArrangementKind.MakeupExam,
+                cancellationToken);
+        return job is null ? NotFound() : Ok(ToArrangementJobResponse(job));
+    }
+
+    [HttpGet("plans/{planId:guid}/arrangement-job")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> GetLatestArrangementJob(
+        Guid planId,
+        CancellationToken cancellationToken)
+    {
+        var job = await db.ExamArrangementJobs.AsNoTracking()
+            .Where(x =>
+                x.PlanId == planId &&
+                x.Kind == ExamArrangementKind.MakeupExam)
+            .OrderByDescending(x => x.CreatedAt)
+            .FirstOrDefaultAsync(cancellationToken);
+        return job is null ? NoContent() : Ok(ToArrangementJobResponse(job));
     }
 
     // ═══════════════════════════════════════════
@@ -315,6 +559,8 @@ public sealed class MakeupExamsController(
         if (plan is null) return NotFound();
         if (plan.Status != MakeupExamPlanStatus.Draft)
             return ConflictProblem("只有草稿状态的补考计划可以自动生成。");
+        if (await FindActiveArrangementJobAsync(planId, cancellationToken) is not null)
+            return ConflictProblem("该计划正在自动编排，请完成后再自动生成场次。");
 
         // Check for existing active job
         var existing = await db.MakeupExamAutoJobs.AsNoTracking()
@@ -336,10 +582,12 @@ public sealed class MakeupExamsController(
             MakeupExamPlanId = planId
         };
         db.MakeupExamAutoJobs.Add(job);
+        db.BackgroundJobOutboxMessages.Add(
+            BackgroundJobOutboxMessage.Create(
+                BackgroundJobKind.MakeupExamAuto,
+                job.Id));
         await db.SaveChangesAsync(cancellationToken);
 
-        autoJobQueue.Enqueue(job.Id);
-
         return AcceptedAtAction(nameof(GetAutoJob), new { jobId = job.Id },
             new { jobId = job.Id, status = job.Status.ToString() });
     }
@@ -553,8 +801,13 @@ public sealed class MakeupExamsController(
                 x.TeachingTask!.TaskNumber,
                 CourseName = x.TeachingTask.Course!.Name,
                 ClassroomName = x.Classroom != null ? x.Classroom.Name : "待分配",
-                x.StartsAt,
+                x.StartsAt
-                Students = x.Enrollments.OrderBy(e => e.Student!.StudentNumber)
+            }).FirstOrDefaultAsync(cancellationToken);
+        if (session is null) return NotFound();
+
+        var students = await db.MakeupExamEnrollments.AsNoTracking()
+            .Where(e => e.MakeupExamSessionId == id)
+            .OrderBy(e => e.Student!.StudentNumber)
             .Select(e => new
             {
                 e.StudentId,
@@ -563,9 +816,28 @@ public sealed class MakeupExamsController(
                 ClassName = e.Student.AdministrativeClass!.Name,
                 e.Reason,
                 e.MakeupScore
-                    }).ToList()
+            })
-            }).FirstOrDefaultAsync(cancellationToken);
+            .ToListAsync(cancellationToken);
-        return session is null ? NotFound() : Ok(session);
+
+        return Ok(new
+        {
+            session.Id,
+            session.TeachingTaskId,
+            session.TaskNumber,
+            session.CourseName,
+            session.ClassroomName,
+            session.StartsAt,
+            Students = students.Select((student, index) => new
+            {
+                student.StudentId,
+                student.StudentNumber,
+                student.Name,
+                student.ClassName,
+                student.Reason,
+                student.MakeupScore,
+                SeatNumber = (index + 1).ToString("D3")
+            })
+        });
     }
 
     // ═══════════════════════════════════════════
@@ -697,7 +969,7 @@ public sealed class MakeupExamsController(
                 .Select(x => (Guid?)x.Id).FirstOrDefaultAsync(cancellationToken);
             if (!studentId.HasValue)
                 return ConflictProblem("当前账号未关联学生档案。");
-            return Ok(await db.MakeupExamEnrollments.AsNoTracking()
+            var schedule = await db.MakeupExamEnrollments.AsNoTracking()
                 .Where(x => x.StudentId == studentId &&
                     x.MakeupExamSession!.MakeupExamPlan!.Status == MakeupExamPlanStatus.Published)
                 .OrderBy(x => x.MakeupExamSession!.ExamDate)
@@ -722,7 +994,49 @@ public sealed class MakeupExamsController(
                     x.MakeupScore,
                     IsMakeup = true
                 })
-                .ToListAsync(cancellationToken));
+                .ToListAsync(cancellationToken);
+            if (schedule.Count == 0) return Ok(schedule);
+
+            var sessionIds = schedule.Select(x => x.Id).Distinct().ToArray();
+            var seatRows = await db.MakeupExamEnrollments.AsNoTracking()
+                .WhereIn(sessionIds, x => x.MakeupExamSessionId)
+                .OrderBy(x => x.Student!.StudentNumber)
+                .Select(x => new
+                {
+                    x.MakeupExamSessionId,
+                    x.StudentId,
+                    x.Student!.StudentNumber
+                })
+                .ToListAsync(cancellationToken);
+            var seatNumbers = seatRows
+                .GroupBy(x => x.MakeupExamSessionId)
+                .SelectMany(group => group.Select((row, index) => new
+                {
+                    row.MakeupExamSessionId,
+                    row.StudentId,
+                    SeatNumber = (index + 1).ToString("D3")
+                }))
+                .ToDictionary(x => (x.MakeupExamSessionId, x.StudentId), x => x.SeatNumber);
+
+            return Ok(schedule.Select(x => new
+            {
+                x.Id,
+                x.PlanName,
+                x.ExamDate,
+                x.StartPeriod,
+                x.PeriodCount,
+                x.StartsAt,
+                x.EndsAt,
+                x.TaskNumber,
+                x.CourseCode,
+                x.CourseName,
+                x.ClassroomName,
+                x.BuildingName,
+                x.Reason,
+                x.MakeupScore,
+                SeatNumber = seatNumbers.GetValueOrDefault((x.Id, studentId.Value)),
+                x.IsMakeup
+            }));
         }
         if (scope.IsInRole(SystemRoles.Teacher))
         {
@@ -895,6 +1209,87 @@ public sealed class MakeupExamsController(
         currentUserDataScope.Current.IsInRole(SystemRoles.SuperAdmin) ||
         currentUserDataScope.Current.IsInRole(SystemRoles.AcademicAdmin);
 
+    private Task<ExamArrangementJob?> FindActiveArrangementJobAsync(
+        Guid planId,
+        CancellationToken cancellationToken) =>
+        db.ExamArrangementJobs.AsNoTracking()
+            .Where(x =>
+                x.Kind == ExamArrangementKind.MakeupExam &&
+                x.ActivePlanId == planId &&
+                (x.Status == ExamArrangementJobStatus.Queued ||
+                 x.Status == ExamArrangementJobStatus.Running))
+            .OrderByDescending(x => x.CreatedAt)
+            .FirstOrDefaultAsync(cancellationToken);
+
+    private ActionResult AcceptedArrangementJob(
+        ExamArrangementJob job,
+        string message) =>
+        AcceptedAtAction(
+            nameof(GetArrangementJob),
+            new { jobId = job.Id },
+            new
+            {
+                jobId = job.Id,
+                status = job.Status.ToString(),
+                message
+            });
+
+    private static object ToArrangementJobResponse(ExamArrangementJob job) => new
+    {
+        job.Id,
+        job.PlanId,
+        Kind = job.Kind.ToString(),
+        Status = job.Status.ToString(),
+        job.TotalSessions,
+        job.ProcessedSessions,
+        job.CurrentStep,
+        job.ResultMessage,
+        job.ErrorMessage,
+        job.AssignClassrooms,
+        job.AssignInvigilators,
+        job.CreatedAt,
+        job.StartedAt,
+        job.CompletedAt
+    };
+
+    private Task<ExamPublishJob?> FindActivePublishJobAsync(
+        Guid planId,
+        CancellationToken cancellationToken) =>
+        db.ExamPublishJobs.AsNoTracking()
+            .Where(x =>
+                x.Kind == ExamPublishJobKind.MakeupExam &&
+                x.ActivePlanId == planId &&
+                (x.Status == ExamPublishJobStatus.Queued ||
+                 x.Status == ExamPublishJobStatus.Running))
+            .OrderByDescending(x => x.CreatedAt)
+            .FirstOrDefaultAsync(cancellationToken);
+
+    private ActionResult AcceptedPublishJob(
+        ExamPublishJob job,
+        string message) =>
+        AcceptedAtAction(
+            nameof(GetPublishJob),
+            new { jobId = job.Id },
+            new
+            {
+                jobId = job.Id,
+                status = job.Status.ToString(),
+                message
+            });
+
+    private static object ToPublishJobResponse(ExamPublishJob job) => new
+    {
+        job.Id,
+        job.PlanId,
+        Kind = job.Kind.ToString(),
+        Status = job.Status.ToString(),
+        job.CurrentStep,
+        job.ErrorMessage,
+        job.CreatedAt,
+        job.StartedAt,
+        job.CompletedAt
+    };
+
     private async Task<ActionResult> SaveAsync(Guid id, bool created,
         CancellationToken token)
     {
@@ -917,6 +1312,10 @@ public sealed class MakeupExamsController(
     });
     private static string? Normalize(string? value) =>
         string.IsNullOrWhiteSpace(value) ? null : value.Trim();
+    private static string? SerializeBuildingIds(IReadOnlyCollection<Guid>? ids) =>
+        ids is { Count: > 0 }
+            ? System.Text.Json.JsonSerializer.Serialize(ids)
+            : null;
 }
 
 // ═══════════════════════════════════════════
@@ -935,10 +1334,21 @@ public sealed record CreateMakeupExamSessionRequest(
     [Range(1, 30)] int StartPeriod,
     [Range(1, 6)] int PeriodCount,
     Guid? RequiredBuildingId,
+    IReadOnlyCollection<Guid>? RequiredBuildingIds,
     [Range(1, 10)] int RequiredInvigilatorCount,
     IReadOnlyCollection<Guid>? InvigilatorIds,
     [MaxLength(500)] string? Notes);
 
+public sealed record CreateMakeupExamSessionsBatchRequest(
+    [Required] IReadOnlyCollection<Guid> TeachingTaskIds,
+    DateOnly ExamDate,
+    [Range(1, 30)] int StartPeriod,
+    [Range(1, 6)] int PeriodCount,
+    Guid? RequiredBuildingId,
+    IReadOnlyCollection<Guid>? RequiredBuildingIds,
+    [Range(1, 10)] int RequiredInvigilatorCount,
+    [MaxLength(500)] string? Notes);
+
 public sealed record EnrollStudentsRequest(
     [Required] IReadOnlyCollection<Guid> StudentIds);
 

src/Jiaowu.Api/Controllers/NotificationsController.cs

@@ -1,4 +1,7 @@
-using System.Security.Claims;
+using System.ComponentModel.DataAnnotations;
+using System.Data;
+using System.Net;
+using System.Text.RegularExpressions;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
@@ -14,20 +17,43 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/notifications")]
 public sealed class NotificationsController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    ILogger<NotificationsController>? logger = null) : ControllerBase
 {
+    private const int MaximumSelectedRecipients = 500;
+    private const int NotificationBatchSize = 300;
+    private const string Senders =
+        SystemRoles.SuperAdmin + "," +
+        SystemRoles.AcademicAdmin + "," +
+        SystemRoles.CollegeAdmin + "," +
+        SystemRoles.Counselor + "," +
+        SystemRoles.Teacher;
+
     [HttpGet]
     public async Task<ActionResult> GetNotifications(
         bool? unreadOnly,
+        NotificationCategory? category,
+        string? keyword,
         int page = 1,
         int pageSize = 20,
         CancellationToken cancellationToken = default)
     {
+        page = Math.Max(1, page);
+        pageSize = Math.Clamp(pageSize, 1, 100);
         var userId = currentUserDataScope.Current.UserId;
         var source = db.Notifications.AsNoTracking()
             .Where(x => x.UserId == userId);
         if (unreadOnly == true)
             source = source.Where(x => !x.IsRead);
+        if (category.HasValue)
+            source = source.Where(x => x.Category == category);
+        if (!string.IsNullOrWhiteSpace(keyword))
+        {
+            var value = keyword.Trim();
+            source = source.Where(x =>
+                x.Title.Contains(value) ||
+                x.Content.Contains(value));
+        }
 
         var total = await source.CountAsync(cancellationToken);
         var items = await source
@@ -36,14 +62,38 @@ public sealed class NotificationsController(
             .Take(pageSize)
             .Select(x => new
             {
-                x.Id, x.Title, x.Content, x.IsRead, x.LinkUrl, x.CreatedAt
+                x.Id,
+                x.Title,
+                x.Content,
+                x.Category,
+                x.IsRead,
+                x.LinkUrl,
+                SenderName = x.MessageDispatch == null
+                    ? "教务系统"
+                    : x.MessageDispatch.SenderName,
+                AudienceName = x.MessageDispatch == null
+                    ? null
+                    : x.MessageDispatch.AudienceName,
+                IsManual = x.MessageDispatchId != null,
+                x.CreatedAt
             })
             .ToListAsync(cancellationToken);
 
         var unreadCount = await db.Notifications
             .CountAsync(x => x.UserId == userId && !x.IsRead, cancellationToken);
+        var unreadByCategory = await db.Notifications.AsNoTracking()
+            .Where(x => x.UserId == userId && !x.IsRead)
+            .GroupBy(x => x.Category)
+            .Select(x => new { Category = x.Key, Count = x.Count() })
+            .ToListAsync(cancellationToken);
 
-        return Ok(new { Items = items, Total = total, UnreadCount = unreadCount });
+        return Ok(new
+        {
+            Items = items,
+            Total = total,
+            UnreadCount = unreadCount,
+            UnreadByCategory = unreadByCategory
+        });
     }
 
     [HttpGet("unread-count")]
@@ -55,30 +105,802 @@ public sealed class NotificationsController(
         return Ok(new { Count = count });
     }
 
+    [HttpGet("composer")]
+    [Authorize(Roles = Senders)]
+    public async Task<ActionResult> GetComposer(CancellationToken cancellationToken)
+    {
+        var scope = currentUserDataScope.Current;
+        if (IsSchoolAdministrator(scope))
+        {
+            return Ok(await BuildAdministratorComposerAsync(
+                scope,
+                null,
+                MessageAudienceType.School,
+                "全校已启用账号",
+                cancellationToken));
+        }
+
+        if (scope.IsInRole(SystemRoles.CollegeAdmin) ||
+            scope.IsInRole(SystemRoles.Counselor))
+        {
+            var collegeId = await ResolveSenderCollegeIdAsync(
+                scope,
+                cancellationToken);
+            if (!collegeId.HasValue)
+            {
+                return ConflictProblem(
+                    "当前账号未关联学院，暂时无法确定发信范围。");
+            }
+
+            var college = await db.Colleges.AsNoTracking()
+                .Where(x => x.Id == collegeId.Value)
+                .Select(x => x.Name)
+                .FirstOrDefaultAsync(cancellationToken);
+            if (college is null)
+                return ConflictProblem("当前账号关联的学院不存在。");
+
+            return Ok(await BuildAdministratorComposerAsync(
+                scope,
+                collegeId.Value,
+                MessageAudienceType.College,
+                $"{college}全院成员",
+                cancellationToken));
+        }
+
+        if (scope.IsInRole(SystemRoles.Teacher))
+        {
+            var tasks = await db.TeachingTasks.AsNoTracking()
+                .Where(task =>
+                    task.Status != TeachingTaskStatus.Draft &&
+                    task.Teachers.Any(item =>
+                        item.Teacher!.UserId == scope.UserId))
+                .OrderByDescending(task => task.AcademicTerm!.IsCurrent)
+                .ThenByDescending(task => task.AcademicTerm!.StartDate)
+                .ThenBy(task => task.TaskNumber)
+                .Select(task => new
+                {
+                    task.Id,
+                    task.TaskNumber,
+                    CourseName = task.Course!.Name,
+                    TermName = task.AcademicTerm!.Name,
+                    RecipientCount = db.Students.Count(student =>
+                        student.Status == StudentStatus.Active &&
+                        student.UserId != null &&
+                        (task.Classes.Any(item =>
+                             item.AdministrativeClassId ==
+                             student.AdministrativeClassId) ||
+                         db.CourseEnrollments.Any(enrollment =>
+                             enrollment.StudentId == student.Id &&
+                             enrollment.Status ==
+                             CourseEnrollmentStatus.Enrolled &&
+                             enrollment.CourseSelectionOffering!
+                                 .TeachingTaskId == task.Id)))
+                })
+                .ToListAsync(cancellationToken);
+            return Ok(new
+            {
+                AudienceType = MessageAudienceType.TeachingTask,
+                AudienceName = "所带教学班",
+                RecipientCount = 0,
+                TeachingTasks = tasks
+            });
+        }
+
+        return Forbid();
+    }
+
+    [HttpGet("recipients")]
+    [Authorize(Roles = Senders)]
+    public async Task<ActionResult> GetRecipients(
+        Guid? collegeId,
+        string? role,
+        Guid? administrativeClassId,
+        Guid? teachingTaskId,
+        string? keyword,
+        int page = 1,
+        int pageSize = 30,
+        CancellationToken cancellationToken = default)
+    {
+        var scope = currentUserDataScope.Current;
+        if (scope.IsInRole(SystemRoles.Teacher) &&
+            !IsSchoolAdministrator(scope) &&
+            !scope.IsInRole(SystemRoles.CollegeAdmin) &&
+            !scope.IsInRole(SystemRoles.Counselor))
+        {
+            return Forbid();
+        }
+
+        var resolvedCollegeId = IsSchoolAdministrator(scope)
+            ? null
+            : await ResolveSenderCollegeIdAsync(scope, cancellationToken);
+        if (!IsSchoolAdministrator(scope) && !resolvedCollegeId.HasValue)
+            return ConflictProblem("当前账号未关联学院，暂时无法确定收件人范围。");
+
+        var filter = new MessageRecipientFilter(
+            collegeId,
+            Normalize(role),
+            administrativeClassId,
+            teachingTaskId,
+            Normalize(keyword));
+        if (filter.Role is not null && !SystemRoles.All.Contains(filter.Role))
+            return ValidationProblem("所选身份类型无效。");
+
+        page = Math.Max(1, page);
+        pageSize = Math.Clamp(pageSize, 10, 100);
+        var source = ApplyRecipientFilter(
+            ScopedRecipientQuery(scope, resolvedCollegeId),
+            filter);
+        var total = await source.CountAsync(cancellationToken);
+        var users = await source
+            .OrderBy(x => x.DisplayName)
+            .ThenBy(x => x.UserName)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .Select(user => new
+            {
+                user.Id,
+                user.DisplayName,
+                user.UserName,
+                user.StaffNumber,
+                CollegeName = db.Colleges
+                    .Where(college => college.Id == user.CollegeId)
+                    .Select(college => college.Name)
+                    .FirstOrDefault(),
+                StudentNumber = db.Students
+                    .Where(student => student.UserId == user.Id)
+                    .Select(student => student.StudentNumber)
+                    .FirstOrDefault(),
+                ClassName = db.Students
+                    .Where(student => student.UserId == user.Id)
+                    .Select(student => student.AdministrativeClass!.Name)
+                    .FirstOrDefault(),
+                TeacherNumber = db.Teachers
+                    .Where(teacher => teacher.UserId == user.Id)
+                    .Select(teacher => teacher.TeacherNumber)
+                    .FirstOrDefault()
+            })
+            .ToListAsync(cancellationToken);
+        var userIds = users.Select(x => x.Id).ToArray();
+        var roleRows = await db.UserRoles.AsNoTracking()
+            .Where(x => userIds.Contains(x.UserId))
+            .Join(
+                db.Roles.AsNoTracking(),
+                userRole => userRole.RoleId,
+                roleEntity => roleEntity.Id,
+                (userRole, roleEntity) => new
+                {
+                    userRole.UserId,
+                    RoleName = roleEntity.Name!
+                })
+            .ToListAsync(cancellationToken);
+        var rolesByUser = roleRows
+            .GroupBy(x => x.UserId)
+            .ToDictionary(
+                group => group.Key,
+                group => group.Select(x => x.RoleName).Distinct().ToArray());
+
+        return Ok(new
+        {
+            Items = users.Select(user => new
+            {
+                user.Id,
+                user.DisplayName,
+                user.UserName,
+                Number = user.StudentNumber ?? user.TeacherNumber ?? user.StaffNumber,
+                user.CollegeName,
+                user.ClassName,
+                Roles = rolesByUser.GetValueOrDefault(user.Id, [])
+            }),
+            Total = total,
+            Page = page,
+            PageSize = pageSize
+        });
+    }
+
+    [HttpPost("send")]
+    [Authorize(Roles = Senders)]
+    public async Task<ActionResult> Send(
+        SendMessageRequest request,
+        CancellationToken cancellationToken)
+    {
+        var title = request.Title.Trim();
+        var content = request.Content.Trim();
+        if (title.Length == 0)
+            return ValidationProblem("请填写消息标题。");
+        if (PlainText(content).Length == 0)
+            return ValidationProblem("请填写消息正文。");
+        if (content.Length > 20000)
+            return ValidationProblem("消息正文过长，请精简至 20000 个字符以内。");
+        var scope = currentUserDataScope.Current;
+        MessageAudienceType audienceType;
+        Guid? audienceId = null;
+        string audienceName;
+        List<Guid> recipientIds;
+
+        if (IsSchoolAdministrator(scope))
+        {
+            var result = await ResolveAdministratorRecipientsAsync(
+                scope,
+                null,
+                request,
+                "全校已启用账号",
+                cancellationToken);
+            if (result.Error is not null) return result.Error;
+            audienceType = result.AudienceType;
+            audienceName = result.AudienceName!;
+            recipientIds = result.RecipientIds!;
+        }
+        else if (scope.IsInRole(SystemRoles.CollegeAdmin) ||
+                 scope.IsInRole(SystemRoles.Counselor))
+        {
+            var collegeId = await ResolveSenderCollegeIdAsync(
+                scope,
+                cancellationToken);
+            if (!collegeId.HasValue)
+            {
+                return ConflictProblem(
+                    "当前账号未关联学院，暂时无法确定发信范围。");
+            }
+
+            var collegeName = await db.Colleges.AsNoTracking()
+                .Where(x => x.Id == collegeId.Value)
+                .Select(x => x.Name)
+                .FirstOrDefaultAsync(cancellationToken);
+            if (collegeName is null)
+                return ConflictProblem("当前账号关联的学院不存在。");
+
+            var result = await ResolveAdministratorRecipientsAsync(
+                scope,
+                collegeId.Value,
+                request,
+                $"{collegeName}全院成员",
+                cancellationToken);
+            if (result.Error is not null) return result.Error;
+            audienceType = result.AudienceType;
+            audienceId = audienceType == MessageAudienceType.College
+                ? collegeId.Value
+                : null;
+            audienceName = result.AudienceName!;
+            recipientIds = result.RecipientIds!;
+        }
+        else if (scope.IsInRole(SystemRoles.Teacher))
+        {
+            if (!request.TeachingTaskId.HasValue)
+                return ValidationProblem("请选择接收消息的教学班。");
+
+            var task = await db.TeachingTasks.AsNoTracking()
+                .Where(x =>
+                    x.Id == request.TeachingTaskId.Value &&
+                    x.Status != TeachingTaskStatus.Draft &&
+                    x.Teachers.Any(item =>
+                        item.Teacher!.UserId == scope.UserId))
+                .Select(x => new
+                {
+                    x.Id,
+                    x.TaskNumber,
+                    CourseName = x.Course!.Name
+                })
+                .FirstOrDefaultAsync(cancellationToken);
+            if (task is null)
+            {
+                return ConflictProblem(
+                    "只能向自己所带且已发布的教学班发信。");
+            }
+
+            audienceType = MessageAudienceType.TeachingTask;
+            audienceId = task.Id;
+            audienceName = $"{task.TaskNumber} · {task.CourseName}";
+            recipientIds = await GetTeachingTaskRecipientIdsAsync(
+                task.Id,
+                cancellationToken);
+        }
+        else
+        {
+            return Forbid();
+        }
+
+        recipientIds = recipientIds.Distinct().ToList();
+        if (recipientIds.Count == 0)
+            return ConflictProblem("当前发信范围内没有可接收消息的已启用账号。");
+
+        var dispatch = new MessageDispatch
+        {
+            SenderUserId = scope.UserId,
+            SenderName = scope.DisplayName ?? "教务用户",
+            Title = title,
+            Content = content,
+            Category = NotificationCategory.General,
+            AudienceType = audienceType,
+            AudienceId = audienceId,
+            AudienceName = audienceName,
+            RecipientCount = recipientIds.Count,
+            LinkUrl = null
+        };
+        try
+        {
+            return await db.ExecuteInRetriableTransactionAsync<ActionResult>(
+                async transaction =>
+                {
+                    db.MessageDispatches.Add(dispatch);
+                    await db.SaveChangesAsync(cancellationToken);
+                    db.ChangeTracker.Clear();
+
+                    foreach (var batch in recipientIds.Chunk(NotificationBatchSize))
+                    {
+                        db.Notifications.AddRange(batch.Select(userId => new Notification
+                        {
+                            UserId = userId,
+                            Title = title,
+                            Content = content,
+                            Category = NotificationCategory.General,
+                            LinkUrl = null,
+                            MessageDispatchId = dispatch.Id
+                        }));
+                        await db.SaveChangesAsync(cancellationToken);
+                        db.ChangeTracker.Clear();
+                    }
+
+                    await transaction.CommitAsync(cancellationToken);
+                    return Ok(new
+                    {
+                        dispatch.Id,
+                        dispatch.AudienceName,
+                        dispatch.RecipientCount,
+                        dispatch.CreatedAt
+                    });
+                },
+                cancellationToken,
+                IsolationLevel.ReadCommitted);
+        }
+        catch (DbUpdateException exception)
+        {
+            logger?.LogError(
+                exception,
+                "Failed to send notification dispatch {DispatchId} to {RecipientCount} recipients.",
+                dispatch.Id,
+                recipientIds.Count);
+            return Problem(
+                title: "消息未能发送",
+                detail: "消息数据保存失败。请确认数据库已完成最新升级后重试；本次消息没有发送。",
+                statusCode: StatusCodes.Status503ServiceUnavailable);
+        }
+    }
+
+    [HttpGet("sent")]
+    [Authorize(Roles = Senders)]
+    public async Task<ActionResult> GetSent(
+        int page = 1,
+        int pageSize = 20,
+        CancellationToken cancellationToken = default)
+    {
+        page = Math.Max(1, page);
+        pageSize = Math.Clamp(pageSize, 1, 100);
+        var userId = currentUserDataScope.Current.UserId;
+        var source = db.MessageDispatches.AsNoTracking()
+            .Where(x => x.SenderUserId == userId);
+        var total = await source.CountAsync(cancellationToken);
+        var items = await source
+            .OrderByDescending(x => x.CreatedAt)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .Select(x => new
+            {
+                x.Id,
+                x.Title,
+                x.Content,
+                x.Category,
+                x.AudienceType,
+                x.AudienceName,
+                x.RecipientCount,
+                x.CreatedAt
+            })
+            .ToListAsync(cancellationToken);
+        return Ok(new { Items = items, Total = total });
+    }
+
     [HttpPost("{id:guid}/read")]
-    public async Task<ActionResult> MarkRead(Guid id, CancellationToken cancellationToken)
+    public async Task<ActionResult> MarkRead(
+        Guid id,
+        CancellationToken cancellationToken)
     {
         var userId = currentUserDataScope.Current.UserId;
-        var n = await db.Notifications
+        var notification = await db.Notifications
-            .FirstOrDefaultAsync(x => x.Id == id && x.UserId == userId, cancellationToken);
+            .FirstOrDefaultAsync(
-        if (n is null) return NotFound();
+                x => x.Id == id && x.UserId == userId,
-        n.IsRead = true;
+                cancellationToken);
+        if (notification is null) return NotFound();
+        notification.IsRead = true;
         await db.SaveChangesAsync(cancellationToken);
         return NoContent();
     }
 
     [HttpPost("read-all")]
-    public async Task<ActionResult> MarkAllRead(CancellationToken cancellationToken)
+    public async Task<ActionResult> MarkAllRead(
+        CancellationToken cancellationToken)
     {
         var userId = currentUserDataScope.Current.UserId;
         await db.Notifications
             .Where(x => x.UserId == userId && !x.IsRead)
-            .ExecuteUpdateAsync(s => s.SetProperty(x => x.IsRead, true),
+            .ExecuteUpdateAsync(
+                updates => updates.SetProperty(x => x.IsRead, true),
                 cancellationToken);
         return NoContent();
     }
+
+    private async Task<List<Guid>> GetTeachingTaskRecipientIdsAsync(
+        Guid teachingTaskId,
+        CancellationToken cancellationToken)
+    {
+        return await db.Students.AsNoTracking()
+            .Where(student =>
+                student.Status == StudentStatus.Active &&
+                student.UserId != null &&
+                db.Users.Any(user =>
+                    user.Id == student.UserId &&
+                    user.IsEnabled) &&
+                (db.TeachingTaskClasses.Any(item =>
+                     item.TeachingTaskId == teachingTaskId &&
+                     item.AdministrativeClassId ==
+                     student.AdministrativeClassId) ||
+                 db.CourseEnrollments.Any(enrollment =>
+                     enrollment.StudentId == student.Id &&
+                     enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                     enrollment.CourseSelectionOffering!.TeachingTaskId ==
+                     teachingTaskId)))
+            .Select(x => x.UserId!.Value)
+            .Distinct()
+            .ToListAsync(cancellationToken);
     }
 
+    private async Task<Guid?> ResolveSenderCollegeIdAsync(
+        CurrentUserScope scope,
+        CancellationToken cancellationToken)
+    {
+        if (scope.CollegeId.HasValue)
+            return scope.CollegeId;
+        if (!scope.IsInRole(SystemRoles.Counselor))
+            return null;
+
+        var collegeIds = await db.AdministrativeClasses.AsNoTracking()
+            .Where(x => x.CounselorUserId == scope.UserId)
+            .Select(x => x.Major!.CollegeId)
+            .Distinct()
+            .Take(2)
+            .ToListAsync(cancellationToken);
+        return collegeIds.Count == 1 ? collegeIds[0] : null;
+    }
+
+    private static bool IsSchoolAdministrator(CurrentUserScope scope) =>
+        scope.IsInRole(SystemRoles.SuperAdmin) ||
+        scope.IsInRole(SystemRoles.AcademicAdmin);
+
+    private async Task<object> BuildAdministratorComposerAsync(
+        CurrentUserScope scope,
+        Guid? fixedCollegeId,
+        MessageAudienceType audienceType,
+        string audienceName,
+        CancellationToken cancellationToken)
+    {
+        var colleges = await db.Colleges.AsNoTracking()
+            .Where(x => !fixedCollegeId.HasValue || x.Id == fixedCollegeId.Value)
+            .OrderBy(x => x.Code)
+            .Select(x => new { x.Id, x.Code, x.Name })
+            .ToListAsync(cancellationToken);
+        var administrativeClasses = await db.AdministrativeClasses.AsNoTracking()
+            .Where(x =>
+                x.IsEnabled &&
+                (!fixedCollegeId.HasValue ||
+                 x.Major!.CollegeId == fixedCollegeId.Value))
+            .OrderByDescending(x => x.Grade)
+            .ThenBy(x => x.Code)
+            .Select(x => new
+            {
+                x.Id,
+                x.Code,
+                x.Name,
+                x.Grade,
+                CollegeId = x.Major!.CollegeId
+            })
+            .ToListAsync(cancellationToken);
+        var teachingTasks = await db.TeachingTasks.AsNoTracking()
+            .Where(x =>
+                x.Status != TeachingTaskStatus.Draft &&
+                (!fixedCollegeId.HasValue ||
+                 x.Course!.CollegeId == fixedCollegeId.Value))
+            .OrderByDescending(x => x.AcademicTerm!.IsCurrent)
+            .ThenByDescending(x => x.AcademicTerm!.StartDate)
+            .ThenBy(x => x.TaskNumber)
+            .Select(x => new
+            {
+                x.Id,
+                x.TaskNumber,
+                CourseName = x.Course!.Name,
+                TermName = x.AcademicTerm!.Name,
+                CollegeId = x.Course.CollegeId
+            })
+            .ToListAsync(cancellationToken);
+        var recipientCount = await ScopedRecipientQuery(scope, fixedCollegeId)
+            .CountAsync(cancellationToken);
+
+        return new
+        {
+            AudienceType = audienceType,
+            AudienceName = audienceName,
+            RecipientCount = recipientCount,
+            CanFilterRecipients = true,
+            MaximumSelectedRecipients,
+            Colleges = colleges,
+            Roles = RoleOptions,
+            AdministrativeClasses = administrativeClasses,
+            TeachingTasks = teachingTasks
+        };
+    }
+
+    private IQueryable<ApplicationUser> ScopedRecipientQuery(
+        CurrentUserScope scope,
+        Guid? fixedCollegeId)
+    {
+        var source = db.Users.AsNoTracking()
+            .Where(x => x.IsEnabled && x.Id != scope.UserId);
+        if (IsSchoolAdministrator(scope)) return source;
+        if (!fixedCollegeId.HasValue) return source.Where(_ => false);
+        var collegeId = fixedCollegeId.Value;
+        return source.Where(user =>
+            user.CollegeId == collegeId ||
+            db.Students.Any(student =>
+                student.UserId == user.Id &&
+                student.AdministrativeClass!.Major!.CollegeId == collegeId) ||
+            db.Teachers.Any(teacher =>
+                teacher.UserId == user.Id &&
+                teacher.CollegeId == collegeId));
+    }
+
+    private IQueryable<ApplicationUser> ApplyRecipientFilter(
+        IQueryable<ApplicationUser> source,
+        MessageRecipientFilter? filter)
+    {
+        if (filter is null) return source;
+        if (filter.CollegeId.HasValue)
+        {
+            var collegeId = filter.CollegeId.Value;
+            source = source.Where(user =>
+                user.CollegeId == collegeId ||
+                db.Students.Any(student =>
+                    student.UserId == user.Id &&
+                    student.AdministrativeClass!.Major!.CollegeId == collegeId) ||
+                db.Teachers.Any(teacher =>
+                    teacher.UserId == user.Id &&
+                    teacher.CollegeId == collegeId));
+        }
+        if (!string.IsNullOrWhiteSpace(filter.Role))
+        {
+            var role = filter.Role;
+            source = source.Where(user =>
+                db.UserRoles.Any(userRole =>
+                    userRole.UserId == user.Id &&
+                    db.Roles.Any(roleEntity =>
+                        roleEntity.Id == userRole.RoleId &&
+                        roleEntity.Name == role)));
+        }
+        if (filter.AdministrativeClassId.HasValue)
+        {
+            var classId = filter.AdministrativeClassId.Value;
+            source = source.Where(user =>
+                db.Students.Any(student =>
+                    student.UserId == user.Id &&
+                    student.AdministrativeClassId == classId));
+        }
+        if (filter.TeachingTaskId.HasValue)
+        {
+            var taskId = filter.TeachingTaskId.Value;
+            source = source.Where(user =>
+                db.Students.Any(student =>
+                    student.UserId == user.Id &&
+                    (db.TeachingTaskClasses.Any(item =>
+                         item.TeachingTaskId == taskId &&
+                         item.AdministrativeClassId ==
+                         student.AdministrativeClassId) ||
+                     db.CourseEnrollments.Any(enrollment =>
+                         enrollment.StudentId == student.Id &&
+                         enrollment.Status == CourseEnrollmentStatus.Enrolled &&
+                         enrollment.CourseSelectionOffering!.TeachingTaskId ==
+                         taskId))));
+        }
+        if (!string.IsNullOrWhiteSpace(filter.Keyword))
+        {
+            var keyword = filter.Keyword;
+            source = source.Where(user =>
+                user.DisplayName.Contains(keyword) ||
+                (user.UserName != null && user.UserName.Contains(keyword)) ||
+                (user.StaffNumber != null && user.StaffNumber.Contains(keyword)) ||
+                db.Students.Any(student =>
+                    student.UserId == user.Id &&
+                    (student.Name.Contains(keyword) ||
+                     student.StudentNumber.Contains(keyword))) ||
+                db.Teachers.Any(teacher =>
+                    teacher.UserId == user.Id &&
+                    (teacher.Name.Contains(keyword) ||
+                     teacher.TeacherNumber.Contains(keyword))));
+        }
+
+        return source;
+    }
+
+    private async Task<RecipientResolution> ResolveAdministratorRecipientsAsync(
+        CurrentUserScope scope,
+        Guid? fixedCollegeId,
+        SendMessageRequest request,
+        string defaultAudienceName,
+        CancellationToken cancellationToken)
+    {
+        var source = ScopedRecipientQuery(scope, fixedCollegeId);
+        if (request.RecipientMode == MessageRecipientMode.Scope)
+        {
+            return new RecipientResolution(
+                fixedCollegeId.HasValue
+                    ? MessageAudienceType.College
+                    : MessageAudienceType.School,
+                defaultAudienceName,
+                await source.Select(x => x.Id).ToListAsync(cancellationToken),
+                null);
+        }
+
+        if (request.RecipientMode == MessageRecipientMode.Filtered)
+        {
+            if (request.RecipientFilter?.Role is not null &&
+                !SystemRoles.All.Contains(request.RecipientFilter.Role))
+            {
+                return new RecipientResolution(
+                    default,
+                    null,
+                    null,
+                    ValidationProblem("所选身份类型无效。"));
+            }
+            var recipientIds = await ApplyRecipientFilter(
+                    source,
+                    request.RecipientFilter)
+                .Select(x => x.Id)
+                .ToListAsync(cancellationToken);
+            return new RecipientResolution(
+                MessageAudienceType.Custom,
+                BuildFilteredAudienceName(request.RecipientFilter),
+                recipientIds,
+                null);
+        }
+
+        if (request.RecipientMode == MessageRecipientMode.Selected)
+        {
+            var requestedIds = request.RecipientUserIds?
+                .Distinct()
+                .ToArray() ?? [];
+            if (requestedIds.Length == 0)
+            {
+                return new RecipientResolution(
+                    default,
+                    null,
+                    null,
+                    ValidationProblem("请至少选择一名收件人。"));
+            }
+            if (requestedIds.Length > MaximumSelectedRecipients)
+            {
+                return new RecipientResolution(
+                    default,
+                    null,
+                    null,
+                    ValidationProblem(
+                        $"单次最多指定 {MaximumSelectedRecipients} 名收件人。"));
+            }
+
+            var authorizedIds = await source
+                .Where(x => requestedIds.Contains(x.Id))
+                .Select(x => x.Id)
+                .ToListAsync(cancellationToken);
+            if (authorizedIds.Count != requestedIds.Length)
+            {
+                return new RecipientResolution(
+                    default,
+                    null,
+                    null,
+                    ValidationProblem("所选收件人包含无权限访问或已停用的账号。"));
+            }
+
+            return new RecipientResolution(
+                MessageAudienceType.Custom,
+                $"指定收件人（{authorizedIds.Count} 人）",
+                authorizedIds,
+                null);
+        }
+
+        return new RecipientResolution(
+            default,
+            null,
+            null,
+            ValidationProblem("请选择有效的收件方式。"));
+    }
+
+    private static string BuildFilteredAudienceName(MessageRecipientFilter? filter)
+    {
+        if (filter is null) return "当前权限范围内全部账号";
+        var parts = new List<string>();
+        if (filter.CollegeId.HasValue) parts.Add("指定学院");
+        if (filter.Role is not null)
+            parts.Add(RoleOptions.FirstOrDefault(x => x.Value == filter.Role)?.Label ??
+                      filter.Role);
+        if (filter.AdministrativeClassId.HasValue) parts.Add("指定行政班");
+        if (filter.TeachingTaskId.HasValue) parts.Add("指定教学班");
+        if (filter.Keyword is not null) parts.Add($"关键词“{filter.Keyword}”");
+        return parts.Count == 0
+            ? "当前权限范围内全部账号"
+            : string.Join(" · ", parts);
+    }
+
+    private static string PlainText(string html)
+    {
+        var withoutTags = Regex.Replace(html, "<[^>]+>", " ");
+        return WebUtility.HtmlDecode(withoutTags).Trim();
+    }
+
+    private static string? Normalize(string? value) =>
+        string.IsNullOrWhiteSpace(value) ? null : value.Trim();
+
+    private static readonly RoleOption[] RoleOptions =
+    [
+        new(SystemRoles.Student, "学生"),
+        new(SystemRoles.Teacher, "任课教师"),
+        new(SystemRoles.Counselor, "辅导员"),
+        new(SystemRoles.CollegeAdmin, "学院管理员"),
+        new(SystemRoles.AcademicAdmin, "校级教务管理员"),
+        new(SystemRoles.Leader, "校领导"),
+        new(SystemRoles.SuperAdmin, "超级管理员")
+    ];
+
+    private ActionResult ConflictProblem(string detail) =>
+        Conflict(new ProblemDetails
+        {
+            Title = "无法发送消息",
+            Detail = detail,
+            Status = StatusCodes.Status409Conflict
+        });
+
+    private ActionResult ValidationProblem(string detail) =>
+        BadRequest(new ProblemDetails
+        {
+            Title = "消息内容不完整",
+            Detail = detail,
+            Status = StatusCodes.Status400BadRequest
+        });
+}
+
+public sealed record SendMessageRequest(
+    [Required, StringLength(200)] string Title,
+    [Required, StringLength(20000)] string Content,
+    Guid? TeachingTaskId = null,
+    MessageRecipientMode RecipientMode = MessageRecipientMode.Scope,
+    MessageRecipientFilter? RecipientFilter = null,
+    IReadOnlyCollection<Guid>? RecipientUserIds = null);
+
+public sealed record MessageRecipientFilter(
+    Guid? CollegeId = null,
+    string? Role = null,
+    Guid? AdministrativeClassId = null,
+    Guid? TeachingTaskId = null,
+    string? Keyword = null);
+
+public enum MessageRecipientMode
+{
+    Scope = 1,
+    Filtered = 2,
+    Selected = 3
+}
+
+public sealed record RoleOption(string Value, string Label);
+
+internal sealed record RecipientResolution(
+    MessageAudienceType AudienceType,
+    string? AudienceName,
+    List<Guid>? RecipientIds,
+    ActionResult? Error);
+
 /// <summary>
 /// Centralized helper to send notifications across the app.
 /// </summary>
@@ -90,13 +912,15 @@ public static class NotificationService
         string title,
         string content,
         string? linkUrl = null,
-        CancellationToken cancellationToken = default)
+        CancellationToken cancellationToken = default,
+        NotificationCategory category = NotificationCategory.General)
     {
         db.Notifications.Add(new Notification
         {
             UserId = userId,
             Title = title,
             Content = content,
+            Category = category,
             LinkUrl = linkUrl
         });
         await db.SaveChangesAsync(cancellationToken);
@@ -109,22 +933,46 @@ public static class NotificationService
         string content,
         Guid? collegeId = null,
         string? linkUrl = null,
-        CancellationToken cancellationToken = default)
+        CancellationToken cancellationToken = default,
+        NotificationCategory category = NotificationCategory.General)
     {
         var query = db.Users
-            .Join(db.UserRoles, u => u.Id, ur => ur.UserId, (u, ur) => new { u.Id, ur.RoleId })
+            .Join(
-            .Join(db.Roles, x => x.RoleId, r => r.Id, (x, r) => new { x.Id, RoleName = r.Name! });
+                db.UserRoles,
-
+                user => user.Id,
-        var userIds = query.Where(x => x.RoleName == roleName);
+                userRole => userRole.UserId,
-
+                (user, userRole) => new
-        if (collegeId.HasValue && roleName == SystemRoles.CollegeAdmin)
                 {
-            userIds = userIds.Where(x =>
+                    user.Id,
-                db.Teachers.Any(t =>
+                    user.IsEnabled,
-                    t.UserId == x.Id && t.CollegeId == collegeId.Value));
+                    user.CollegeId,
+                    userRole.RoleId
+                })
+            .Join(
+                db.Roles,
+                item => item.RoleId,
+                role => role.Id,
+                (item, role) => new
+                {
+                    item.Id,
+                    item.IsEnabled,
+                    item.CollegeId,
+                    RoleName = role.Name!
+                });
+
+        var userIds = query.Where(x =>
+            x.RoleName == roleName &&
+            x.IsEnabled);
+
+        if (collegeId.HasValue)
+        {
+            userIds = userIds.Where(x => x.CollegeId == collegeId.Value);
         }
 
-        var ids = await userIds.Select(x => x.Id).Distinct().ToListAsync(cancellationToken);
+        var ids = await userIds
+            .Select(x => x.Id)
+            .Distinct()
+            .ToListAsync(cancellationToken);
         foreach (var id in ids)
         {
             db.Notifications.Add(new Notification
@@ -132,6 +980,7 @@ public static class NotificationService
                 UserId = id,
                 Title = title,
                 Content = content,
+                Category = category,
                 LinkUrl = linkUrl
             });
         }
@@ -144,7 +993,8 @@ public static class NotificationService
         string title,
         string content,
         string? linkUrl = null,
-        CancellationToken cancellationToken = default)
+        CancellationToken cancellationToken = default,
+        NotificationCategory category = NotificationCategory.General)
     {
         foreach (var userId in userIds.Distinct())
         {
@@ -153,6 +1003,7 @@ public static class NotificationService
                 UserId = userId,
                 Title = title,
                 Content = content,
+                Category = category,
                 LinkUrl = linkUrl
             });
         }

src/Jiaowu.Api/Controllers/OfficialDocumentsController.cs

@@ -0,0 +1,413 @@
+using System.ComponentModel.DataAnnotations;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.OfficialDocuments;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.RateLimiting;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Options;
+
+namespace Jiaowu.Api.Controllers;
+
+[ApiController]
+[Route("api/official-documents")]
+public sealed class OfficialDocumentsController(
+    AppDbContext db,
+    ICurrentUserDataScope currentUserDataScope,
+    OfficialDocumentService service,
+    IOptions<OfficialDocumentOptions> options) : ControllerBase
+{
+    private const string Managers =
+        SystemRoles.SuperAdmin + "," +
+        SystemRoles.AcademicAdmin + "," +
+        SystemRoles.CollegeAdmin;
+    private const string Readers = Managers + "," + SystemRoles.Student;
+
+    [HttpGet]
+    [Authorize(Roles = Readers)]
+    public async Task<ActionResult> List(
+        OfficialDocumentType? type,
+        OfficialDocumentStatus? status,
+        Guid? studentId,
+        CancellationToken cancellationToken)
+    {
+        var source = AccessibleDocuments().AsNoTracking();
+        if (type.HasValue) source = source.Where(x => x.Type == type);
+        if (status.HasValue) source = source.Where(x => x.Status == status);
+        if (studentId.HasValue) source = source.Where(x => x.StudentId == studentId);
+
+        return Ok(await source
+            .OrderByDescending(x => x.IssuedAt)
+            .Select(x => new
+            {
+                x.Id,
+                x.DocumentNumber,
+                x.Type,
+                x.Status,
+                x.StudentId,
+                x.Student!.StudentNumber,
+                StudentName = x.Student.Name,
+                CollegeName = x.Student.AdministrativeClass!.Major!.College!.Name,
+                x.Purpose,
+                x.IssuedAt,
+                IssuedByName = x.Student.UserId == x.IssuedByUserId
+                    ? "学生自助服务"
+                    : x.IssuedByUser!.DisplayName,
+                x.InvalidatedAt,
+                x.InvalidationReason,
+                x.ReissuedFromDocumentId,
+                DownloadCount = x.Downloads.Count,
+                LastDownloadedAt = x.Downloads.Max(download => (DateTime?)download.CreatedAt)
+            })
+            .ToListAsync(cancellationToken));
+    }
+
+    [HttpGet("students/options")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> StudentOptions(
+        string? keyword,
+        CancellationToken cancellationToken)
+    {
+        var source = AccessibleStudents().AsNoTracking();
+        if (!string.IsNullOrWhiteSpace(keyword))
+        {
+            var value = keyword.Trim();
+            source = source.Where(x =>
+                x.StudentNumber.Contains(value) || x.Name.Contains(value));
+        }
+
+        return Ok(await source.OrderBy(x => x.StudentNumber)
+            .Select(x => new
+            {
+                x.Id,
+                x.StudentNumber,
+                x.Name,
+                x.Status,
+                ClassName = x.AdministrativeClass!.Name,
+                MajorName = x.AdministrativeClass.Major!.Name,
+                CollegeName = x.AdministrativeClass.Major.College!.Name
+            })
+            .ToListAsync(cancellationToken));
+    }
+
+    [HttpPost]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> Issue(
+        IssueOfficialDocumentRequest request,
+        CancellationToken cancellationToken)
+    {
+        if (!await AccessibleStudents().AnyAsync(x => x.Id == request.StudentId, cancellationToken))
+            return NotFound();
+
+        try
+        {
+            var document = await service.CreateAsync(
+                request.StudentId,
+                request.Type,
+                request.Purpose,
+                currentUserDataScope.Current.UserId,
+                currentUserDataScope.Current.DisplayName ?? "教务管理员",
+                VerificationBaseUrl(),
+                null,
+                cancellationToken);
+            db.OfficialDocuments.Add(document);
+            await db.SaveChangesAsync(cancellationToken);
+            return CreatedAtAction(nameof(Download), new { id = document.Id },
+                new { document.Id, document.DocumentNumber });
+        }
+        catch (OfficialDocumentValidationException exception)
+        {
+            return ConflictProblem(exception.Message);
+        }
+    }
+
+    [HttpPost("mine")]
+    [Authorize(Roles = SystemRoles.Student)]
+    public async Task<ActionResult> IssueMine(
+        SelfIssueOfficialDocumentRequest request,
+        CancellationToken cancellationToken)
+    {
+        var userId = currentUserDataScope.Current.UserId;
+        var studentId = await db.Students.AsNoTracking()
+            .Where(x => x.UserId == userId)
+            .Select(x => (Guid?)x.Id)
+            .SingleOrDefaultAsync(cancellationToken);
+        if (!studentId.HasValue)
+            return ConflictProblem("当前账号未关联有效学生档案，不能申请电子凭证。");
+
+        var purpose = string.IsNullOrWhiteSpace(request.Purpose)
+            ? null
+            : request.Purpose.Trim();
+        var duplicateThreshold = DateTime.UtcNow.AddMinutes(-5);
+        var recentDocument = await db.OfficialDocuments.AsNoTracking()
+            .Where(x =>
+                x.StudentId == studentId.Value &&
+                x.Type == request.Type &&
+                x.Status == OfficialDocumentStatus.Valid &&
+                x.Purpose == purpose &&
+                x.IssuedAt >= duplicateThreshold)
+            .OrderByDescending(x => x.IssuedAt)
+            .Select(x => new { x.Id, x.DocumentNumber })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (recentDocument is not null)
+            return Ok(new
+            {
+                recentDocument.Id,
+                recentDocument.DocumentNumber,
+                Reused = true
+            });
+
+        try
+        {
+            var document = await service.CreateAsync(
+                studentId.Value,
+                request.Type,
+                purpose,
+                userId,
+                $"{options.Value.IssuingOffice}自助签发",
+                VerificationBaseUrl(),
+                null,
+                cancellationToken);
+            db.OfficialDocuments.Add(document);
+            await db.SaveChangesAsync(cancellationToken);
+            return CreatedAtAction(nameof(Download), new { id = document.Id },
+                new { document.Id, document.DocumentNumber, Reused = false });
+        }
+        catch (OfficialDocumentValidationException exception)
+        {
+            return ConflictProblem(exception.Message);
+        }
+    }
+
+    [HttpGet("{id:guid}/download")]
+    [Authorize(Roles = Readers)]
+    public async Task<IActionResult> Download(Guid id, CancellationToken cancellationToken)
+    {
+        var document = await AccessibleDocuments()
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (document is null) return NotFound();
+        if (document.Status != OfficialDocumentStatus.Valid)
+            return ConflictProblem("该凭证已经失效或被新凭证替代，不能继续下载。");
+
+        db.OfficialDocumentDownloads.Add(new OfficialDocumentDownload
+        {
+            OfficialDocumentId = document.Id,
+            DownloadedByUserId = currentUserDataScope.Current.UserId,
+            IpAddress = HttpContext.Connection.RemoteIpAddress?.ToString(),
+            UserAgent = Request.Headers.UserAgent.ToString()
+        });
+        await db.SaveChangesAsync(cancellationToken);
+        return File(document.PdfContent, "application/pdf", $"{document.DocumentNumber}.pdf");
+    }
+
+    [HttpGet("{id:guid}/downloads")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> DownloadHistory(
+        Guid id,
+        CancellationToken cancellationToken)
+    {
+        if (!await AccessibleDocuments().AnyAsync(x => x.Id == id, cancellationToken))
+            return NotFound();
+
+        return Ok(await db.OfficialDocumentDownloads.AsNoTracking()
+            .Where(x => x.OfficialDocumentId == id)
+            .OrderByDescending(x => x.CreatedAt)
+            .Select(x => new
+            {
+                x.Id,
+                x.CreatedAt,
+                x.DownloadedByUserId,
+                DownloadedByName = x.DownloadedByUser!.DisplayName,
+                x.IpAddress,
+                x.UserAgent
+            })
+            .ToListAsync(cancellationToken));
+    }
+
+    [HttpPost("{id:guid}/invalidate")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> Invalidate(
+        Guid id,
+        InvalidateOfficialDocumentRequest request,
+        CancellationToken cancellationToken)
+    {
+        var document = await AccessibleDocuments()
+            .FirstOrDefaultAsync(x => x.Id == id, cancellationToken);
+        if (document is null) return NotFound();
+        if (document.Status != OfficialDocumentStatus.Valid)
+            return ConflictProblem("该凭证当前已不是有效状态。");
+
+        document.Status = OfficialDocumentStatus.Invalidated;
+        document.InvalidatedAt = DateTime.UtcNow;
+        document.InvalidatedByUserId = currentUserDataScope.Current.UserId;
+        document.InvalidationReason = request.Reason.Trim();
+        await db.SaveChangesAsync(cancellationToken);
+        return Ok(new { document.Id, document.Status, document.InvalidatedAt });
+    }
+
+    [HttpPost("{id:guid}/reissue")]
+    [Authorize(Roles = Managers)]
+    public async Task<ActionResult> Reissue(
+        Guid id,
+        ReissueOfficialDocumentRequest request,
+        CancellationToken cancellationToken)
+    {
+        try
+        {
+            var newDocument = await db.ExecuteInRetriableTransactionAsync(async transaction =>
+            {
+                var original = await AccessibleDocuments()
+                    .FirstOrDefaultAsync(x => x.Id == id, cancellationToken)
+                    ?? throw new OfficialDocumentNotFoundException();
+                if (await db.OfficialDocuments.AnyAsync(
+                        x => x.ReissuedFromDocumentId == original.Id,
+                        cancellationToken))
+                    throw new OfficialDocumentValidationException("该凭证已经重签过，不能重复重签。");
+
+                var replacement = await service.CreateAsync(
+                    original.StudentId,
+                    original.Type,
+                    request.Purpose ?? original.Purpose,
+                    currentUserDataScope.Current.UserId,
+                    currentUserDataScope.Current.DisplayName ?? "教务管理员",
+                    VerificationBaseUrl(),
+                    original.Id,
+                    cancellationToken);
+                original.Status = OfficialDocumentStatus.Superseded;
+                original.InvalidatedAt = DateTime.UtcNow;
+                original.InvalidatedByUserId = currentUserDataScope.Current.UserId;
+                original.InvalidationReason = request.Reason.Trim();
+                db.OfficialDocuments.Add(replacement);
+                await db.SaveChangesAsync(cancellationToken);
+                await transaction.CommitAsync(cancellationToken);
+                return replacement;
+            }, cancellationToken);
+
+            return Ok(new { newDocument.Id, newDocument.DocumentNumber });
+        }
+        catch (OfficialDocumentNotFoundException)
+        {
+            return NotFound();
+        }
+        catch (OfficialDocumentValidationException exception)
+        {
+            return ConflictProblem(exception.Message);
+        }
+    }
+
+    [HttpGet("verify/{verificationCode}")]
+    [AllowAnonymous]
+    [EnableRateLimiting("official-verification")]
+    public async Task<ActionResult> Verify(
+        string verificationCode,
+        CancellationToken cancellationToken)
+    {
+        var normalized = verificationCode.Trim();
+        if (normalized.Length is < 12 or > 128)
+            return Ok(new { Found = false, Valid = false });
+
+        var hash = OfficialDocumentService.HashVerificationCode(normalized);
+        var documentNumber = normalized.ToUpperInvariant();
+        var document = await db.OfficialDocuments.AsNoTracking()
+            .FirstOrDefaultAsync(x =>
+                x.VerificationCodeHash == hash ||
+                x.DocumentNumber == documentNumber,
+                cancellationToken);
+        if (document is null) return Ok(new { Found = false, Valid = false });
+
+        var snapshot = OfficialDocumentService.DeserializeSnapshot(document.SnapshotJson);
+        var replacementNumber = await db.OfficialDocuments.AsNoTracking()
+            .Where(x => x.ReissuedFromDocumentId == document.Id)
+            .Select(x => x.DocumentNumber)
+            .FirstOrDefaultAsync(cancellationToken);
+        return Ok(new
+        {
+            Found = true,
+            Valid = document.Status == OfficialDocumentStatus.Valid,
+            document.Status,
+            document.DocumentNumber,
+            document.Type,
+            snapshot.InstitutionName,
+            StudentName = MaskName(snapshot.Student.Name),
+            StudentNumber = MaskStudentNumber(snapshot.Student.StudentNumber),
+            snapshot.Student.CollegeName,
+            snapshot.Student.MajorName,
+            document.IssuedAt,
+            document.InvalidatedAt,
+            ReplacementDocumentNumber = replacementNumber,
+            PdfSha256 = document.PdfSha256
+        });
+    }
+
+    private IQueryable<OfficialDocument> AccessibleDocuments()
+    {
+        var scope = currentUserDataScope.Current;
+        var source = db.OfficialDocuments.AsQueryable();
+        var isManager = scope.IsInRole(SystemRoles.SuperAdmin) ||
+                        scope.IsInRole(SystemRoles.AcademicAdmin) ||
+                        scope.IsInRole(SystemRoles.CollegeAdmin);
+        if (scope.IsInRole(SystemRoles.Student) && !isManager)
+            return source.Where(x => x.Student!.UserId == scope.UserId);
+        if (scope.RestrictedCollegeId.HasValue)
+            return source.Where(x =>
+                x.Student!.AdministrativeClass!.Major!.CollegeId ==
+                scope.RestrictedCollegeId.Value);
+        return source;
+    }
+
+    private IQueryable<Student> AccessibleStudents()
+    {
+        var source = db.Students.AsQueryable();
+        var collegeId = currentUserDataScope.Current.RestrictedCollegeId;
+        return collegeId.HasValue
+            ? source.Where(x => x.AdministrativeClass!.Major!.CollegeId == collegeId.Value)
+            : source;
+    }
+
+    private string VerificationBaseUrl()
+    {
+        var configured = options.Value.PublicBaseUrl;
+        if (!string.IsNullOrWhiteSpace(configured)) return configured.TrimEnd('/');
+        return $"{Request.Scheme}://{Request.Host}{Request.PathBase}";
+    }
+
+    private static string MaskName(string name) => name.Length switch
+    {
+        0 => "*",
+        1 => name,
+        2 => name[0] + "*",
+        _ => name[0] + new string('*', name.Length - 2) + name[^1]
+    };
+
+    private static string MaskStudentNumber(string number) => number.Length <= 4
+        ? new string('*', number.Length)
+        : number[..2] + new string('*', number.Length - 4) + number[^2..];
+
+    private ConflictObjectResult ConflictProblem(string detail) => Conflict(new ProblemDetails
+    {
+        Title = "当前状态不允许此操作",
+        Detail = detail,
+        Status = StatusCodes.Status409Conflict
+    });
+}
+
+public sealed record IssueOfficialDocumentRequest(
+    Guid StudentId,
+    OfficialDocumentType Type,
+    [param: StringLength(200)] string? Purpose);
+
+public sealed record SelfIssueOfficialDocumentRequest(
+    OfficialDocumentType Type,
+    [param: StringLength(200)] string? Purpose);
+
+public sealed record InvalidateOfficialDocumentRequest(
+    [param: Required, StringLength(500, MinimumLength = 2)] string Reason);
+
+public sealed record ReissueOfficialDocumentRequest(
+    [param: Required, StringLength(500, MinimumLength = 2)] string Reason,
+    [param: StringLength(200)] string? Purpose);
+
+file sealed class OfficialDocumentNotFoundException : Exception;

src/Jiaowu.Api/Controllers/OperationsController.cs

@@ -0,0 +1,606 @@
+using System.ComponentModel.DataAnnotations;
+using Jiaowu.Api.Contracts;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Domain.System;
+using Jiaowu.Api.Infrastructure.Operations;
+using Jiaowu.Api.Infrastructure.Observability;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Controllers;
+
+[ApiController]
+[Authorize(Roles = SystemRoles.SuperAdmin)]
+[Route("api/operations")]
+public sealed class OperationsController(
+    AppDbContext db,
+    OperationalHealthService healthService,
+    DatabaseBackupService backupService,
+    PerformanceReportService performanceReportService,
+    OperationsOptions options) : ControllerBase
+{
+    [HttpGet("performance")]
+    public async Task<ActionResult<PerformanceReport>> GetPerformance(
+        [FromQuery] string? range = "1h",
+        CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            return Ok(await performanceReportService.GetAsync(
+                range,
+                cancellationToken));
+        }
+        catch (ArgumentOutOfRangeException)
+        {
+            return ValidationProblem(
+                "性能报表范围仅支持 15m、1h、24h 或 7d。");
+        }
+    }
+
+    [HttpGet("summary")]
+    public async Task<ActionResult<OperationsSummary>> GetSummary(
+        CancellationToken cancellationToken)
+    {
+        var since = DateTime.UtcNow.AddHours(-24);
+        var health = await healthService.CheckAsync(cancellationToken);
+        var backups = await backupService.ListAsync(cancellationToken);
+        var auditCount = await db.AuditLogs.AsNoTracking()
+            .CountAsync(x => x.CreatedAt >= since, cancellationToken);
+        var serverErrorCount = await db.AuditLogs.AsNoTracking()
+            .CountAsync(
+                x => x.CreatedAt >= since && x.StatusCode >= 500,
+                cancellationToken);
+        var failedJobCount = await CountFailedJobsAsync(
+            DateTime.UtcNow.AddDays(-7),
+            cancellationToken);
+        var alerts = await BuildAlertsAsync(
+            health,
+            backups,
+            serverErrorCount,
+            failedJobCount,
+            cancellationToken);
+        return Ok(new OperationsSummary(
+            DateTime.UtcNow,
+            health,
+            new OperationsCounters(
+                auditCount,
+                serverErrorCount,
+                failedJobCount,
+                alerts.Count(x => x.Severity == "critical")),
+            alerts,
+            backups.FirstOrDefault()));
+    }
+
+    [HttpGet("health")]
+    public async Task<ActionResult<OperationalHealthSnapshot>> GetHealth(
+        CancellationToken cancellationToken) =>
+        Ok(await healthService.CheckAsync(cancellationToken));
+
+    [HttpGet("audit-logs")]
+    public async Task<ActionResult<PagedResult<AuditLogItem>>> GetAuditLogs(
+        [FromQuery] int page = 1,
+        [FromQuery] int pageSize = 20,
+        [FromQuery] string? method = null,
+        [FromQuery] int? statusCode = null,
+        [FromQuery] string? userName = null,
+        [FromQuery] string? path = null,
+        [FromQuery] DateTime? from = null,
+        [FromQuery] DateTime? to = null,
+        CancellationToken cancellationToken = default)
+    {
+        var pagingError = ValidatePaging(page, pageSize);
+        if (pagingError is not null) return pagingError;
+        var rangeError = ValidateRange(from, to);
+        if (rangeError is not null) return rangeError;
+
+        var query = db.AuditLogs.AsNoTracking().AsQueryable();
+        if (!string.IsNullOrWhiteSpace(method))
+        {
+            var normalizedMethod = method.Trim().ToUpperInvariant();
+            query = query.Where(x => x.Method == normalizedMethod);
+        }
+        if (statusCode.HasValue)
+            query = query.Where(x => x.StatusCode == statusCode.Value);
+        if (!string.IsNullOrWhiteSpace(userName))
+        {
+            var normalizedUser = userName.Trim();
+            query = query.Where(x =>
+                x.UserName != null && x.UserName.Contains(normalizedUser));
+        }
+        if (!string.IsNullOrWhiteSpace(path))
+        {
+            var normalizedPath = path.Trim();
+            query = query.Where(x => x.Path.Contains(normalizedPath));
+        }
+        query = query.Where(x =>
+            x.CreatedAt >= (from ?? DateTime.UtcNow.AddDays(-1)));
+        if (to.HasValue)
+            query = query.Where(x => x.CreatedAt <= to.Value);
+
+        var total = await query.CountAsync(cancellationToken);
+        var items = await query
+            .OrderByDescending(x => x.CreatedAt)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .Select(x => new AuditLogItem(
+                x.Id,
+                x.UserName,
+                x.Method,
+                x.Path,
+                x.StatusCode,
+                x.IpAddress,
+                x.CreatedAt))
+            .ToListAsync(cancellationToken);
+        return Ok(new PagedResult<AuditLogItem>(items, total, page, pageSize));
+    }
+
+    [HttpGet("failed-jobs")]
+    public async Task<ActionResult<PagedResult<FailedBackgroundJobItem>>>
+        GetFailedJobs(
+            [FromQuery] int page = 1,
+            [FromQuery] int pageSize = 20,
+            [FromQuery] string? kind = null,
+            [FromQuery] DateTime? from = null,
+            [FromQuery] DateTime? to = null,
+            CancellationToken cancellationToken = default)
+    {
+        var pagingError = ValidatePaging(page, pageSize);
+        if (pagingError is not null) return pagingError;
+        var rangeError = ValidateRange(from, to);
+        if (rangeError is not null) return rangeError;
+
+        var normalizedKind = NormalizeJobKind(kind);
+        if (kind is not null && normalizedKind is null)
+            return ValidationProblem("后台任务类型无效。");
+
+        var effectiveFrom = from ?? DateTime.UtcNow.AddDays(-30);
+        var take = checked(page * pageSize);
+        var rows = new List<FailedBackgroundJobItem>();
+        var total = 0;
+
+        if (normalizedKind is null or "AutomaticSchedule")
+        {
+            var query = db.AutomaticScheduleJobs.AsNoTracking()
+                .Where(x =>
+                    x.Status == AutomaticScheduleJobStatus.Failed &&
+                    x.CreatedAt >= effectiveFrom);
+            if (to.HasValue) query = query.Where(x => x.CreatedAt <= to.Value);
+            total += await query.CountAsync(cancellationToken);
+            rows.AddRange(await query
+                .OrderByDescending(x => x.CompletedAt ?? x.UpdatedAt)
+                .Take(take)
+                .Select(x => new FailedBackgroundJobItem(
+                    x.Id,
+                    "AutomaticSchedule",
+                    "自动排课",
+                    x.SchedulePlan == null ? "排课方案" : x.SchedulePlan.Name,
+                    x.ErrorMessage ?? "任务失败但未记录错误详情。",
+                    x.CreatedAt,
+                    x.StartedAt,
+                    x.CompletedAt,
+                    0))
+                .ToListAsync(cancellationToken));
+        }
+
+        if (normalizedKind is null or "SchedulePublish")
+        {
+            var query = db.SchedulePublishJobs.AsNoTracking()
+                .Where(x =>
+                    x.Status == SchedulePublishJobStatus.Failed &&
+                    x.CreatedAt >= effectiveFrom);
+            if (to.HasValue) query = query.Where(x => x.CreatedAt <= to.Value);
+            total += await query.CountAsync(cancellationToken);
+            rows.AddRange(await query
+                .OrderByDescending(x => x.CompletedAt ?? x.UpdatedAt)
+                .Take(take)
+                .Select(x => new FailedBackgroundJobItem(
+                    x.Id,
+                    "SchedulePublish",
+                    "课表发布",
+                    x.SchedulePlan == null ? "排课方案" : x.SchedulePlan.Name,
+                    x.ErrorMessage ?? "任务失败但未记录错误详情。",
+                    x.CreatedAt,
+                    x.StartedAt,
+                    x.CompletedAt,
+                    0))
+                .ToListAsync(cancellationToken));
+        }
+
+        if (normalizedKind is null or "MakeupExamAuto")
+        {
+            var query = db.MakeupExamAutoJobs.AsNoTracking()
+                .Where(x =>
+                    x.Status == MakeupExamAutoJobStatus.Failed &&
+                    x.CreatedAt >= effectiveFrom);
+            if (to.HasValue) query = query.Where(x => x.CreatedAt <= to.Value);
+            total += await query.CountAsync(cancellationToken);
+            rows.AddRange(await query
+                .OrderByDescending(x => x.CompletedAt ?? x.UpdatedAt)
+                .Take(take)
+                .Select(x => new FailedBackgroundJobItem(
+                    x.Id,
+                    "MakeupExamAuto",
+                    "补考自动安排",
+                    x.MakeupExamPlan == null ? "补考计划" : x.MakeupExamPlan.Name,
+                    x.ErrorMessage ?? "任务失败但未记录错误详情。",
+                    x.CreatedAt,
+                    x.StartedAt,
+                    x.CompletedAt,
+                    0))
+                .ToListAsync(cancellationToken));
+        }
+
+        if (normalizedKind is null or "ExamArrangement")
+        {
+            var query = db.ExamArrangementJobs.AsNoTracking()
+                .Where(x =>
+                    x.Status == ExamArrangementJobStatus.Failed &&
+                    x.CreatedAt >= effectiveFrom);
+            if (to.HasValue) query = query.Where(x => x.CreatedAt <= to.Value);
+            total += await query.CountAsync(cancellationToken);
+            rows.AddRange(await query
+                .OrderByDescending(x => x.CompletedAt ?? x.UpdatedAt)
+                .Take(take)
+                .Select(x => new FailedBackgroundJobItem(
+                    x.Id,
+                    "ExamArrangement",
+                    x.Kind == ExamArrangementKind.FormalExam
+                        ? "正式考试编排"
+                        : "补考编排",
+                    x.Kind == ExamArrangementKind.FormalExam
+                        ? "正式考试计划"
+                        : "补考计划",
+                    x.ErrorMessage ?? "任务失败但未记录错误详情。",
+                    x.CreatedAt,
+                    x.StartedAt,
+                    x.CompletedAt,
+                    0))
+                .ToListAsync(cancellationToken));
+        }
+
+        if (normalizedKind is null or "ExamPublish")
+        {
+            var query = db.ExamPublishJobs.AsNoTracking()
+                .Where(x =>
+                    x.Status == ExamPublishJobStatus.Failed &&
+                    x.CreatedAt >= effectiveFrom);
+            if (to.HasValue) query = query.Where(x => x.CreatedAt <= to.Value);
+            total += await query.CountAsync(cancellationToken);
+            rows.AddRange(await query
+                .OrderByDescending(x => x.CompletedAt ?? x.UpdatedAt)
+                .Take(take)
+                .Select(x => new FailedBackgroundJobItem(
+                    x.Id,
+                    "ExamPublish",
+                    x.Kind == ExamPublishJobKind.FormalExam
+                        ? "正式考试发布"
+                        : "补考发布",
+                    x.Kind == ExamPublishJobKind.FormalExam
+                        ? "正式考试计划"
+                        : "补考计划",
+                    x.ErrorMessage ?? "任务失败但未记录错误详情。",
+                    x.CreatedAt,
+                    x.StartedAt,
+                    x.CompletedAt,
+                    0))
+                .ToListAsync(cancellationToken));
+        }
+
+        var pageItems = rows
+            .OrderByDescending(x => x.CompletedAt ?? x.CreatedAt)
+            .Skip((page - 1) * pageSize)
+            .Take(pageSize)
+            .ToArray();
+        if (pageItems.Length > 0)
+        {
+            var ids = pageItems.Select(x => x.Id).ToArray();
+            var attempts = await db.BackgroundJobOutboxMessages.AsNoTracking()
+                .Where(x => ids.Contains(x.JobId))
+                .Select(x => new { x.JobId, x.ProcessingAttempts })
+                .ToDictionaryAsync(x => x.JobId, x => x.ProcessingAttempts,
+                    cancellationToken);
+            pageItems = pageItems
+                .Select(x => x with
+                {
+                    ProcessingAttempts = attempts.GetValueOrDefault(x.Id)
+                })
+                .ToArray();
+        }
+
+        return Ok(new PagedResult<FailedBackgroundJobItem>(
+            pageItems,
+            total,
+            page,
+            pageSize));
+    }
+
+    [HttpGet("backups")]
+    public async Task<ActionResult<IReadOnlyCollection<BackupArtifact>>> GetBackups(
+        CancellationToken cancellationToken) =>
+        Ok(await backupService.ListAsync(cancellationToken));
+
+    [HttpPost("backups")]
+    public async Task<ActionResult<BackupArtifact>> CreateBackup(
+        CreateBackupRequest request,
+        CancellationToken cancellationToken)
+    {
+        try
+        {
+            var artifact = await backupService.CreateAsync(
+                request.Note,
+                cancellationToken);
+            return CreatedAtAction(
+                nameof(GetBackups),
+                new { id = artifact.Id },
+                artifact);
+        }
+        catch (Exception exception) when (exception is not OperationCanceledException)
+        {
+            return Problem(
+                title: "数据库备份失败",
+                detail: SafeMessage(exception),
+                statusCode: StatusCodes.Status503ServiceUnavailable);
+        }
+    }
+
+    [HttpPost("backups/{backupId}/restore-drill")]
+    public async Task<ActionResult<RestoreDrillResult>> RunRestoreDrill(
+        string backupId,
+        RestoreDrillRequest request,
+        CancellationToken cancellationToken)
+    {
+        if (!request.Confirmation.Equals(
+                "RESTORE_DRILL",
+                StringComparison.Ordinal))
+        {
+            return ValidationProblem(
+                "恢复演练必须明确确认，且不会覆盖当前业务数据库。");
+        }
+
+        try
+        {
+            return Ok(await backupService.RunRestoreDrillAsync(
+                backupId,
+                cancellationToken));
+        }
+        catch (FileNotFoundException)
+        {
+            return NotFound(new ProblemDetails
+            {
+                Title = "备份不存在",
+                Detail = "指定备份不存在或其文件已被移除。",
+                Status = StatusCodes.Status404NotFound
+            });
+        }
+    }
+
+    private async Task<IReadOnlyCollection<OperationalAlert>> BuildAlertsAsync(
+        OperationalHealthSnapshot health,
+        IReadOnlyCollection<BackupArtifact> backups,
+        int serverErrorCount,
+        int failedJobCount,
+        CancellationToken cancellationToken)
+    {
+        var alerts = health.Components
+            .Where(x => x.Status != "healthy")
+            .Select(x => new OperationalAlert(
+                $"health-{x.Key}",
+                x.Status == "unhealthy" ? "critical" : "warning",
+                "health",
+                $"{x.Label}状态异常",
+                x.Detail,
+                health.CheckedAt))
+            .ToList();
+
+        if (serverErrorCount > 0)
+        {
+            var latest = await db.AuditLogs.AsNoTracking()
+                .Where(x =>
+                    x.CreatedAt >= DateTime.UtcNow.AddHours(-24) &&
+                    x.StatusCode >= 500)
+                .OrderByDescending(x => x.CreatedAt)
+                .Select(x => new { x.Path, x.StatusCode, x.CreatedAt })
+                .FirstOrDefaultAsync(cancellationToken);
+            alerts.Add(new OperationalAlert(
+                "http-5xx",
+                "critical",
+                "audit",
+                $"过去 24 小时发生 {serverErrorCount} 次服务端错误",
+                latest is null
+                    ? "请检查服务日志定位异常。"
+                    : $"最近一次为 {latest.StatusCode} {latest.Path}。",
+                latest?.CreatedAt ?? DateTime.UtcNow));
+        }
+
+        if (failedJobCount > 0)
+        {
+            alerts.Add(new OperationalAlert(
+                "failed-jobs",
+                "critical",
+                "jobs",
+                $"最近 7 天有 {failedJobCount} 个后台任务失败",
+                "任务已停止或达到重试上限，请在失败任务中查看错误详情。",
+                DateTime.UtcNow));
+        }
+
+        var retryingFailures = await db.BackgroundJobOutboxMessages.AsNoTracking()
+            .CountAsync(
+                x => x.State != BackgroundJobOutboxState.Completed &&
+                     x.LastError != null,
+                cancellationToken);
+        if (retryingFailures > 0)
+        {
+            alerts.Add(new OperationalAlert(
+                "retrying-jobs",
+                "warning",
+                "jobs",
+                $"{retryingFailures} 个后台任务正在错误重试",
+                "任务队列仍会自动重试；若持续出现，请检查依赖服务与任务参数。",
+                DateTime.UtcNow));
+        }
+
+        var latestBackup = backups.FirstOrDefault();
+        if (latestBackup is null)
+        {
+            alerts.Add(new OperationalAlert(
+                "backup-missing",
+                "critical",
+                "backup",
+                "尚无可验证的数据库备份",
+                "立即创建首个备份，并在创建后执行一次隔离恢复演练。",
+                DateTime.UtcNow));
+        }
+        else
+        {
+            var ageHours = (DateTime.UtcNow - latestBackup.CreatedAt).TotalHours;
+            if (ageHours > options.BackupWarningHours)
+            {
+                alerts.Add(new OperationalAlert(
+                    "backup-stale",
+                    "warning",
+                    "backup",
+                    $"最近备份已超过 {options.BackupWarningHours} 小时",
+                    $"最近备份创建于 {latestBackup.CreatedAt:u}。",
+                    latestBackup.CreatedAt));
+            }
+            if (latestBackup.LastDrillSucceeded == false)
+            {
+                alerts.Add(new OperationalAlert(
+                    "restore-drill-failed",
+                    "critical",
+                    "backup",
+                    "最近一次恢复演练失败",
+                    latestBackup.LastDrillDetail ?? "请重新运行演练并检查数据库工具日志。",
+                    latestBackup.LastDrillAt ?? latestBackup.CreatedAt));
+            }
+            else if (!latestBackup.LastDrillAt.HasValue)
+            {
+                alerts.Add(new OperationalAlert(
+                    "restore-drill-missing",
+                    "warning",
+                    "backup",
+                    "最近备份尚未完成恢复演练",
+                    "恢复演练只写入隔离数据库，不会覆盖当前业务数据。",
+                    latestBackup.CreatedAt));
+            }
+        }
+
+        return alerts
+            .OrderBy(x => x.Severity == "critical" ? 0 : 1)
+            .ThenByDescending(x => x.OccurredAt)
+            .ToArray();
+    }
+
+    private async Task<int> CountFailedJobsAsync(
+        DateTime from,
+        CancellationToken cancellationToken) =>
+        await db.AutomaticScheduleJobs.AsNoTracking()
+            .CountAsync(
+                x => x.Status == AutomaticScheduleJobStatus.Failed &&
+                     x.CreatedAt >= from,
+                cancellationToken) +
+        await db.SchedulePublishJobs.AsNoTracking()
+            .CountAsync(
+                x => x.Status == SchedulePublishJobStatus.Failed &&
+                     x.CreatedAt >= from,
+                cancellationToken) +
+        await db.MakeupExamAutoJobs.AsNoTracking()
+            .CountAsync(
+                x => x.Status == MakeupExamAutoJobStatus.Failed &&
+                     x.CreatedAt >= from,
+                cancellationToken) +
+        await db.ExamArrangementJobs.AsNoTracking()
+            .CountAsync(
+                x => x.Status == ExamArrangementJobStatus.Failed &&
+                     x.CreatedAt >= from,
+                cancellationToken) +
+        await db.ExamPublishJobs.AsNoTracking()
+            .CountAsync(
+                x => x.Status == ExamPublishJobStatus.Failed &&
+                     x.CreatedAt >= from,
+                cancellationToken);
+
+    private ActionResult? ValidatePaging(int page, int pageSize)
+    {
+        if (page is < 1 or > 100000 || pageSize is < 1 or > 100)
+        {
+            return ValidationProblem(
+                "页码必须在 1 到 100000 之间，每页数量必须在 1 到 100 之间。");
+        }
+        return null;
+    }
+
+    private ActionResult? ValidateRange(DateTime? from, DateTime? to)
+    {
+        if (from.HasValue && to.HasValue && from.Value > to.Value)
+            return ValidationProblem("开始时间不能晚于结束时间。");
+        return null;
+    }
+
+    private static string? NormalizeJobKind(string? kind)
+    {
+        if (string.IsNullOrWhiteSpace(kind)) return null;
+        return kind.Trim() switch
+        {
+            "AutomaticSchedule" => "AutomaticSchedule",
+            "SchedulePublish" => "SchedulePublish",
+            "MakeupExamAuto" => "MakeupExamAuto",
+            "ExamArrangement" => "ExamArrangement",
+            _ => null
+        };
+    }
+
+    private static string SafeMessage(Exception exception)
+    {
+        var message = exception.GetBaseException().Message;
+        return message.Length <= 500 ? message : message[..500];
+    }
+}
+
+public sealed record AuditLogItem(
+    Guid Id,
+    string? UserName,
+    string Method,
+    string Path,
+    int StatusCode,
+    string? IpAddress,
+    DateTime CreatedAt);
+
+public sealed record FailedBackgroundJobItem(
+    Guid Id,
+    string Kind,
+    string KindLabel,
+    string Context,
+    string ErrorMessage,
+    DateTime CreatedAt,
+    DateTime? StartedAt,
+    DateTime? CompletedAt,
+    int ProcessingAttempts);
+
+public sealed record OperationalAlert(
+    string Id,
+    string Severity,
+    string Source,
+    string Title,
+    string Detail,
+    DateTime OccurredAt);
+
+public sealed record OperationsCounters(
+    int AuditEvents24Hours,
+    int ServerErrors24Hours,
+    int FailedJobs7Days,
+    int CriticalAlerts);
+
+public sealed record OperationsSummary(
+    DateTime GeneratedAt,
+    OperationalHealthSnapshot Health,
+    OperationsCounters Counters,
+    IReadOnlyCollection<OperationalAlert> Alerts,
+    BackupArtifact? LatestBackup);
+
+public sealed record CreateBackupRequest([MaxLength(200)] string? Note);
+
+public sealed record RestoreDrillRequest([Required] string Confirmation);

src/Jiaowu.Api/Controllers/PersonnelController.cs

@@ -3,6 +3,7 @@ using Jiaowu.Api.Contracts;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Identity;
@@ -17,7 +18,8 @@ namespace Jiaowu.Api.Controllers;
 public sealed class PersonnelController(
     AppDbContext db,
     ICurrentUserDataScope currentUserDataScope,
-    UserManager<ApplicationUser> userManager) : ControllerBase
+    UserManager<ApplicationUser> userManager,
+    IAppCache cache) : ControllerBase
 {
     private const string ReadRoles =
         SystemRoles.SuperAdmin + "," +
@@ -209,6 +211,9 @@ public sealed class PersonnelController(
                 teacher.UserId = user.Id;
                 await db.SaveChangesAsync(cancellationToken);
                 await transaction.CommitAsync(cancellationToken);
+                await cache.RemoveByTagAsync(
+                    AppCacheTags.Timetables,
+                    cancellationToken);
                 return Ok(new { user.Id, UserName = userName });
             },
             cancellationToken);
@@ -429,6 +434,12 @@ public sealed class PersonnelController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(
+                AppCacheTags.Timetables,
+                cancellationToken);
+            await cache.RemoveByTagAsync(
+                AppCacheTags.Analytics,
+                cancellationToken);
             return Created(string.Empty, new { id });
         }
         catch (DbUpdateException)
@@ -442,6 +453,12 @@ public sealed class PersonnelController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(
+                AppCacheTags.Timetables,
+                cancellationToken);
+            await cache.RemoveByTagAsync(
+                AppCacheTags.Analytics,
+                cancellationToken);
             return NoContent();
         }
         catch (DbUpdateException)

src/Jiaowu.Api/Controllers/PersonnelExcelController.cs

@@ -1,6 +1,7 @@
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
@@ -14,7 +15,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/personnel")]
 public sealed class PersonnelExcelController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache cache) : ControllerBase
 {
     private const string ReadRoles =
         SystemRoles.SuperAdmin + "," +
@@ -142,6 +144,12 @@ public sealed class PersonnelExcelController(
                     }
                     await db.SaveChangesAsync(cancellationToken);
                     await transaction.CommitAsync(cancellationToken);
+                    await cache.RemoveByTagAsync(
+                        AppCacheTags.Timetables,
+                        cancellationToken);
+                    await cache.RemoveByTagAsync(
+                        AppCacheTags.Analytics,
+                        cancellationToken);
                     return Ok(result);
                 }
                 catch (DbUpdateException)

src/Jiaowu.Api/Controllers/ScheduleSettingsController.cs

@@ -1,6 +1,7 @@
 using System.ComponentModel.DataAnnotations;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
@@ -11,7 +12,7 @@ namespace Jiaowu.Api.Controllers;
 [ApiController]
 [Authorize(Roles = SystemRoles.SuperAdmin + "," + SystemRoles.AcademicAdmin)]
 [Route("api/schedules")]
-public sealed class ScheduleSettingsController(AppDbContext db) : ControllerBase
+public sealed class ScheduleSettingsController(AppDbContext db, IAppCache cache) : ControllerBase
 {
     [HttpGet("time-slots")]
     public async Task<ActionResult> GetTimeSlots(
@@ -65,6 +66,7 @@ public sealed class ScheduleSettingsController(AppDbContext db) : ControllerBase
             IsEnabled = request.IsEnabled
         }));
         await db.SaveChangesAsync(cancellationToken);
+        await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
         return NoContent();
     }
 
@@ -94,6 +96,8 @@ public sealed class ScheduleSettingsController(AppDbContext db) : ControllerBase
                 x.StartWeek,
                 x.EndWeek,
                 x.WeeklyHours,
+                CourseTotalHours = x.Course.TotalHours,
+                CoursePracticeHours = x.Course.PracticeHours,
                 x.SchedulingMode
             })
             .ToListAsync(cancellationToken);
@@ -119,6 +123,8 @@ public sealed class ScheduleSettingsController(AppDbContext db) : ControllerBase
                 task.StartWeek,
                 task.EndWeek,
                 task.WeeklyHours,
+                task.CourseTotalHours,
+                task.CoursePracticeHours,
                 task.SchedulingMode,
                 HasCustomConstraint = constraint is not null,
                 RequiresClassroom = task.SchedulingMode == TeachingTaskSchedulingMode.Flexible

src/Jiaowu.Api/Controllers/SchedulesController.cs

@@ -3,8 +3,10 @@ using System.Security.Claims;
 using System.Text.Json;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Domain.System;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Scheduling;
+using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
@@ -15,9 +17,7 @@ namespace Jiaowu.Api.Controllers;
 [Authorize(Roles = ManagementRoles)]
 [Route("api/schedules")]
 public sealed class SchedulesController(
-    AppDbContext db,
+    AppDbContext db) : ControllerBase
-    AutomaticScheduleJobQueue automaticScheduleJobQueue,
-    SchedulePublishJobQueue schedulePublishJobQueue) : ControllerBase
 {
     private const string ManagementRoles =
         SystemRoles.SuperAdmin + "," +
@@ -71,6 +71,7 @@ public sealed class SchedulesController(
                     {
                         entry.Id,
                         entry.TeachingTaskId,
+                        entry.Kind,
                         TaskNumber = entry.TeachingTask!.TaskNumber,
                         TaskName = entry.TeachingTask.Name,
                         CourseCode = entry.TeachingTask.Course!.Code,
@@ -167,6 +168,7 @@ public sealed class SchedulesController(
             Entries = source.Entries.Select(entry => new ScheduleEntry
             {
                 TeachingTaskId = entry.TeachingTaskId,
+                Kind = entry.Kind,
                 ClassroomId = entry.ClassroomId,
                 DayOfWeek = entry.DayOfWeek,
                 StartPeriod = entry.StartPeriod,
@@ -241,6 +243,10 @@ public sealed class SchedulesController(
             CurrentStep = "等待后台检查"
         };
         db.SchedulePublishJobs.Add(job);
+        db.BackgroundJobOutboxMessages.Add(
+            BackgroundJobOutboxMessage.Create(
+                BackgroundJobKind.SchedulePublish,
+                job.Id));
         try
         {
             await db.SaveChangesAsync(cancellationToken);
@@ -263,7 +269,6 @@ public sealed class SchedulesController(
                 ToResponse(existing));
         }
 
-        schedulePublishJobQueue.Enqueue(job.Id);
         return AcceptedAtAction(
             nameof(GetSchedulePublishJob),
             new { jobId = job.Id },
@@ -321,6 +326,10 @@ public sealed class SchedulesController(
             RequestedByUserId = requestedByUserId
         };
         db.AutomaticScheduleJobs.Add(job);
+        db.BackgroundJobOutboxMessages.Add(
+            BackgroundJobOutboxMessage.Create(
+                BackgroundJobKind.AutomaticSchedule,
+                job.Id));
         try
         {
             await db.SaveChangesAsync(cancellationToken);
@@ -339,7 +348,6 @@ public sealed class SchedulesController(
                 ToResponse(existing));
         }
 
-        automaticScheduleJobQueue.Enqueue(job.Id);
         return AcceptedAtAction(
             nameof(GetAutomaticScheduleJob),
             new { jobId = job.Id },
@@ -413,6 +421,7 @@ public sealed class SchedulesController(
         var validation = await ValidateEntryAsync(plan, entryId, request, cancellationToken);
         if (validation is not null) return validation;
         entry.TeachingTaskId = request.TeachingTaskId;
+        entry.Kind = request.Kind;
         entry.ClassroomId = request.ClassroomId;
         entry.DayOfWeek = request.DayOfWeek;
         entry.StartPeriod = request.StartPeriod;
@@ -492,6 +501,7 @@ public sealed class SchedulesController(
             .Include(x => x.Classes)
             .ThenInclude(x => x.AdministrativeClass)
             .ThenInclude(x => x!.Students)
+            .Include(x => x.Course)
             .FirstOrDefaultAsync(x => x.Id == request.TeachingTaskId, cancellationToken);
          if (task is null ||
              task.Status != TeachingTaskStatus.Published ||
@@ -501,13 +511,52 @@ public sealed class SchedulesController(
              return ValidationProblem("非排时课程不进入正常课表，无需设置星期、节次或教室。");
         if (request.StartWeek < task.StartWeek || request.EndWeek > task.EndWeek)
             return ValidationProblem("排课周次必须位于教学任务的授课周次内。");
+        var targetHours = TeachingTaskHours.TargetHours(
+            task.Course!,
+            request.Kind);
+        if (targetHours == 0)
+            return ValidationProblem(
+                request.Kind == ScheduleEntryKind.Experiment
+                    ? "该课程没有实践学时，不能安排实验课。"
+                    : "该课程没有理论学时，不能安排理论课。");
+        var existingEntries = await db.ScheduleEntries.AsNoTracking()
+            .Where(x =>
+                x.SchedulePlanId == plan.Id &&
+                x.TeachingTaskId == request.TeachingTaskId &&
+                x.Kind == request.Kind &&
+                x.Id != entryId)
+            .Select(x => new
+            {
+                x.StartWeek,
+                x.EndWeek,
+                x.WeekPattern,
+                x.PeriodCount
+            })
+            .ToListAsync(cancellationToken);
+        var existingHours = existingEntries.Sum(x =>
+            TeachingTaskHours.ScheduledHours(
+                x.StartWeek,
+                x.EndWeek,
+                x.WeekPattern,
+                x.PeriodCount));
+        var proposedHours = TeachingTaskHours.ScheduledHours(
+            request.StartWeek,
+            request.EndWeek,
+            request.WeekPattern,
+            request.PeriodCount);
+        if (existingHours + proposedHours > targetHours)
+            return ValidationProblem(
+                $"该教学任务{(request.Kind == ScheduleEntryKind.Experiment ? "实验" : "理论")}课" +
+                $"共需 {targetHours} 学时；当前操作后将达到 " +
+                $"{existingHours + proposedHours} 学时。");
 
         var constraint = await db.TeachingTaskScheduleConstraints.AsNoTracking()
             .Include(x => x.AllowedClassrooms)
             .FirstOrDefaultAsync(
                 x => x.TeachingTaskId == request.TeachingTaskId,
                 cancellationToken);
-        var requiresClassroom = constraint?.RequiresClassroom ?? true;
+        var requiresClassroom = request.Kind == ScheduleEntryKind.Experiment ||
+                                constraint?.RequiresClassroom != false;
         if (requiresClassroom && !request.ClassroomId.HasValue)
             return ValidationProblem("该课程需要占用教室，请选择教室。");
         if (!requiresClassroom && request.ClassroomId.HasValue)
@@ -531,6 +580,10 @@ public sealed class SchedulesController(
                     x => x.Id == request.ClassroomId && x.IsEnabled,
                     cancellationToken);
             if (classroom is null) return ValidationProblem("所选教室不存在或已停用。");
+            if (request.Kind == ScheduleEntryKind.Experiment &&
+                !IsExperimentRoom(classroom.RoomType))
+                return ValidationProblem(
+                    $"实验课必须安排在实验室、实训室或机房；“{classroom.Name}”的场地类型为“{classroom.RoomType}”。");
             if (constraint?.RequiredCampusId is Guid campusId &&
                 classroom.Building!.CampusId != campusId)
                 return ValidationProblem("所选教室不在该课程指定的校区。");
@@ -584,6 +637,7 @@ public sealed class SchedulesController(
         {
             SchedulePlanId = planId,
             TeachingTaskId = request.TeachingTaskId,
+            Kind = request.Kind,
             ClassroomId = request.ClassroomId,
             DayOfWeek = request.DayOfWeek,
             StartPeriod = request.StartPeriod,
@@ -601,6 +655,12 @@ public sealed class SchedulesController(
                 .Select(int.Parse)
                 .ToHashSet();
 
+    private static bool IsExperimentRoom(string roomType) =>
+        roomType.Contains("实验", StringComparison.OrdinalIgnoreCase) ||
+        roomType.Contains("实训", StringComparison.OrdinalIgnoreCase) ||
+        roomType.Contains("机房", StringComparison.OrdinalIgnoreCase) ||
+        roomType.Contains("语音", StringComparison.OrdinalIgnoreCase);
+
     private async Task<ActionResult> SaveAsync(
         Guid id,
         bool created,
@@ -698,7 +758,8 @@ public sealed record ScheduleEntryRequest(
     [Range(1, 30)] int StartWeek,
     [Range(1, 30)] int EndWeek,
     WeekPattern WeekPattern,
-    [MaxLength(500)] string? Notes);
+    [MaxLength(500)] string? Notes,
+    ScheduleEntryKind Kind = ScheduleEntryKind.Lecture);
 
 public sealed record AutomaticScheduleJobResponse(
     Guid Id,

src/Jiaowu.Api/Controllers/StatisticsController.cs

@@ -1,6 +1,8 @@
+using System.Text.Json;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Authorization;
@@ -14,7 +16,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/statistics")]
 public sealed class StatisticsController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache appCache) : ControllerBase
 {
     private const string ViewerRoles =
         SystemRoles.SuperAdmin + "," +
@@ -22,7 +25,12 @@ public sealed class StatisticsController(
         SystemRoles.CollegeAdmin + "," +
         SystemRoles.Leader;
 
-    private Guid? RestrictedCollegeId => currentUserDataScope.Current.RestrictedCollegeId;
+    // HybridCache may execute its source factory without the request's ambient
+    // HttpContext. Keep the authorization scope stable for the whole controller
+    // invocation instead of resolving it again inside that background factory.
+    private readonly CurrentUserScope currentUser = currentUserDataScope.Current;
+
+    private Guid? RestrictedCollegeId => currentUser.RestrictedCollegeId;
 
     private Guid? ResolveCollegeId(Guid? requestedCollegeId)
     {
@@ -34,14 +42,49 @@ public sealed class StatisticsController(
     // ── 1. Student Statistics ────────────────────────────────────────
 
     [HttpGet("students/summary")]
-    public async Task<ActionResult<object>> GetStudentSummary(
+    public Task<ActionResult<object>> GetStudentSummary(
         Guid? collegeId, Guid? majorId, Guid? classId,
         int? grade, int? enrollmentYear,
+        CancellationToken cancellationToken) =>
+        GetStudentSummaryCore(
+            collegeId,
+            majorId,
+            classId,
+            grade,
+            enrollmentYear,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetStudentSummaryCore(
+        Guid? collegeId, Guid? majorId, Guid? classId,
+        int? grade, int? enrollmentYear,
+        bool useCache,
         CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "students",
+                    effectiveCollegeId,
+                    KeyPart(majorId),
+                    KeyPart(classId),
+                    KeyPart(grade),
+                    KeyPart(enrollmentYear)),
+                token => GetStudentSummaryCore(
+                    collegeId,
+                    majorId,
+                    classId,
+                    grade,
+                    enrollmentYear,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var baseQuery = db.Students.AsNoTracking()
             .Where(s => effectiveCollegeId == null ||
                 s.AdministrativeClass!.Major!.CollegeId == effectiveCollegeId)
@@ -112,8 +155,16 @@ public sealed class StatisticsController(
         int? grade, int? enrollmentYear,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetStudentSummary(collegeId, majorId, classId, grade, enrollmentYear, cancellationToken)
+        var summary = await GetStudentSummaryCore(
-            .ConfigureAwait(false)).Value!;
+            collegeId,
+            majorId,
+            classId,
+            grade,
+            enrollmentYear,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("学生统计", new()
         {
             { "各学院人数", ((IEnumerable<dynamic>)data.byCollege).Select(x => new object?[] { x.collegeName, x.count }) },
@@ -128,13 +179,41 @@ public sealed class StatisticsController(
     // ── 2. Course Statistics ─────────────────────────────────────────
 
     [HttpGet("courses/summary")]
-    public async Task<ActionResult<object>> GetCourseSummary(
+    public Task<ActionResult<object>> GetCourseSummary(
         Guid? collegeId, Guid? categoryId, CourseNature? nature,
+        CancellationToken cancellationToken) =>
+        GetCourseSummaryCore(
+            collegeId,
+            categoryId,
+            nature,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetCourseSummaryCore(
+        Guid? collegeId, Guid? categoryId, CourseNature? nature,
+        bool useCache,
         CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "courses",
+                    effectiveCollegeId,
+                    KeyPart(categoryId),
+                    KeyPart(nature)),
+                token => GetCourseSummaryCore(
+                    collegeId,
+                    categoryId,
+                    nature,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var baseQuery = db.Courses.AsNoTracking()
             .Where(c => effectiveCollegeId == null || c.CollegeId == effectiveCollegeId)
             .Where(c => categoryId == null || c.CourseCategoryId == categoryId)
@@ -184,8 +263,14 @@ public sealed class StatisticsController(
         Guid? collegeId, Guid? categoryId, CourseNature? nature,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetCourseSummary(collegeId, categoryId, nature, cancellationToken)
+        var summary = await GetCourseSummaryCore(
-            .ConfigureAwait(false)).Value!;
+            collegeId,
+            categoryId,
+            nature,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("课程统计", new()
         {
             { "各学院课程数", ((IEnumerable<dynamic>)data.byCollege).Select(x => new object?[] { x.collegeName, x.count }) },
@@ -199,13 +284,46 @@ public sealed class StatisticsController(
     // ── 3. Grade Statistics ──────────────────────────────────────────
 
     [HttpGet("grades/summary")]
-    public async Task<ActionResult<object>> GetGradeSummary(
+    public Task<ActionResult<object>> GetGradeSummary(
         Guid? academicTermId, Guid? collegeId, Guid? majorId, Guid? classId,
-        Guid? courseId, CancellationToken cancellationToken)
+        Guid? courseId, CancellationToken cancellationToken) =>
+        GetGradeSummaryCore(
+            academicTermId,
+            collegeId,
+            majorId,
+            classId,
+            courseId,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetGradeSummaryCore(
+        Guid? academicTermId, Guid? collegeId, Guid? majorId, Guid? classId,
+        Guid? courseId, bool useCache, CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "grades",
+                    effectiveCollegeId,
+                    KeyPart(academicTermId),
+                    KeyPart(majorId),
+                    KeyPart(classId),
+                    KeyPart(courseId)),
+                token => GetGradeSummaryCore(
+                    academicTermId,
+                    collegeId,
+                    majorId,
+                    classId,
+                    courseId,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var recordsQuery = db.GradeRecords.AsNoTracking()
             .Where(r => r.GradeSheet!.Status == GradeSheetStatus.Published)
             .Where(r => academicTermId == null || r.GradeSheet!.TeachingTask!.AcademicTermId == academicTermId)
@@ -302,8 +420,16 @@ public sealed class StatisticsController(
         Guid? academicTermId, Guid? collegeId, Guid? majorId, Guid? classId,
         Guid? courseId, CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetGradeSummary(academicTermId, collegeId, majorId, classId, courseId, cancellationToken)
+        var summary = await GetGradeSummaryCore(
-            .ConfigureAwait(false)).Value!;
+            academicTermId,
+            collegeId,
+            majorId,
+            classId,
+            courseId,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("成绩统计", new()
         {
             { "分数段分布", ((IEnumerable<dynamic>)data.scoreDistribution).Select(x => new object?[] { x.label, x.count }) },
@@ -317,13 +443,41 @@ public sealed class StatisticsController(
     // ── 4. Pass Rate Statistics ──────────────────────────────────────
 
     [HttpGet("pass-rates/summary")]
-    public async Task<ActionResult<object>> GetPassRateSummary(
+    public Task<ActionResult<object>> GetPassRateSummary(
         Guid? academicTermId, Guid? collegeId, Guid? courseId,
+        CancellationToken cancellationToken) =>
+        GetPassRateSummaryCore(
+            academicTermId,
+            collegeId,
+            courseId,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetPassRateSummaryCore(
+        Guid? academicTermId, Guid? collegeId, Guid? courseId,
+        bool useCache,
         CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "pass-rates",
+                    effectiveCollegeId,
+                    KeyPart(academicTermId),
+                    KeyPart(courseId)),
+                token => GetPassRateSummaryCore(
+                    academicTermId,
+                    collegeId,
+                    courseId,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var recordsQuery = db.GradeRecords.AsNoTracking()
             .Where(r => r.GradeSheet!.Status == GradeSheetStatus.Published)
             .Where(r => academicTermId == null || r.GradeSheet!.TeachingTask!.AcademicTermId == academicTermId)
@@ -425,8 +579,14 @@ public sealed class StatisticsController(
         Guid? academicTermId, Guid? collegeId, Guid? courseId,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetPassRateSummary(academicTermId, collegeId, courseId, cancellationToken)
+        var summary = await GetPassRateSummaryCore(
-            .ConfigureAwait(false)).Value!;
+            academicTermId,
+            collegeId,
+            courseId,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("通过率统计", new()
         {
             { "各学院通过率", ((IEnumerable<dynamic>)data.byCollege).Select(x => new object?[] { x.collegeName, x.passRate, x.total }) },
@@ -439,13 +599,38 @@ public sealed class StatisticsController(
     // ── 5. Teacher Workload Statistics ───────────────────────────────
 
     [HttpGet("teacher-workload/summary")]
-    public async Task<ActionResult<object>> GetTeacherWorkloadSummary(
+    public Task<ActionResult<object>> GetTeacherWorkloadSummary(
         Guid? academicTermId, Guid? collegeId,
+        CancellationToken cancellationToken) =>
+        GetTeacherWorkloadSummaryCore(
+            academicTermId,
+            collegeId,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetTeacherWorkloadSummaryCore(
+        Guid? academicTermId, Guid? collegeId,
+        bool useCache,
         CancellationToken cancellationToken)
     {
         var effectiveCollegeId = ResolveCollegeId(collegeId);
         if (collegeId.HasValue && effectiveCollegeId != collegeId) return Forbid();
 
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "teacher-workload",
+                    effectiveCollegeId,
+                    KeyPart(academicTermId)),
+                token => GetTeacherWorkloadSummaryCore(
+                    academicTermId,
+                    collegeId,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         var tasks = await db.TeachingTaskTeachers.AsNoTracking()
             .Where(tt => academicTermId == null || tt.TeachingTask!.AcademicTermId == academicTermId)
             .Where(tt => effectiveCollegeId == null || tt.Teacher!.CollegeId == effectiveCollegeId)
@@ -524,8 +709,13 @@ public sealed class StatisticsController(
         Guid? academicTermId, Guid? collegeId,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetTeacherWorkloadSummary(academicTermId, collegeId, cancellationToken)
+        var summary = await GetTeacherWorkloadSummaryCore(
-            .ConfigureAwait(false)).Value!;
+            academicTermId,
+            collegeId,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("教师工作量统计", new()
         {
             { "教师明细", ((IEnumerable<dynamic>)data.byTeacher).Select(x => new object?[] { x.teacherName, x.teacherNumber, x.collegeName, x.title, x.totalHours, x.courseCount, x.taskCount }) },
@@ -537,10 +727,39 @@ public sealed class StatisticsController(
     // ── 6. Classroom Utilization Statistics ──────────────────────────
 
     [HttpGet("classroom-utilization/summary")]
-    public async Task<ActionResult<object>> GetClassroomUtilizationSummary(
+    public Task<ActionResult<object>> GetClassroomUtilizationSummary(
         Guid? academicTermId, Guid? buildingId, Guid? campusId,
+        CancellationToken cancellationToken) =>
+        GetClassroomUtilizationSummaryCore(
+            academicTermId,
+            buildingId,
+            campusId,
+            useCache: true,
+            cancellationToken);
+
+    private async Task<ActionResult<object>> GetClassroomUtilizationSummaryCore(
+        Guid? academicTermId, Guid? buildingId, Guid? campusId,
+        bool useCache,
         CancellationToken cancellationToken)
     {
+        if (useCache)
+        {
+            return await GetCachedSummaryAsync(
+                StatisticsKey(
+                    "classroom-utilization",
+                    RestrictedCollegeId,
+                    KeyPart(academicTermId),
+                    KeyPart(buildingId),
+                    KeyPart(campusId)),
+                token => GetClassroomUtilizationSummaryCore(
+                    academicTermId,
+                    buildingId,
+                    campusId,
+                    useCache: false,
+                    token),
+                cancellationToken);
+        }
+
         // Find published schedule plan
         var planQuery = db.SchedulePlans.AsNoTracking()
             .Where(p => p.Status == SchedulePlanStatus.Published);
@@ -713,8 +932,14 @@ public sealed class StatisticsController(
         Guid? academicTermId, Guid? buildingId, Guid? campusId,
         CancellationToken cancellationToken)
     {
-        var data = (dynamic)(await GetClassroomUtilizationSummary(academicTermId, buildingId, campusId, cancellationToken)
+        var summary = await GetClassroomUtilizationSummaryCore(
-            .ConfigureAwait(false)).Value!;
+            academicTermId,
+            buildingId,
+            campusId,
+            useCache: false,
+            cancellationToken);
+        if (summary.Result is not null) return summary.Result;
+        var data = (dynamic)summary.Value!;
         return ExportSummary("教室利用率统计", new()
         {
             { "各教学楼", ((IEnumerable<dynamic>)data.byBuilding).Select(x => new object?[] { x.buildingName, x.totalClassrooms, x.utilizationRate, x.totalUsedPeriods, x.totalAvailablePeriods }) },
@@ -727,6 +952,55 @@ public sealed class StatisticsController(
 
     // ── Helpers ──────────────────────────────────────────────────────
 
+    private async Task<ActionResult<object>> GetCachedSummaryAsync(
+        string key,
+        Func<CancellationToken, Task<ActionResult<object>>> factory,
+        CancellationToken cancellationToken)
+    {
+        var value = await appCache.GetOrCreateAsync(
+            key,
+            async token =>
+            {
+                var source = await factory(token);
+                var data = source.Result is ObjectResult { Value: not null } objectResult
+                    ? objectResult.Value
+                    : source.Value;
+                if (data is null)
+                    throw new InvalidOperationException(
+                        "Statistics cache source did not return a successful value.");
+
+                return JsonSerializer.SerializeToElement(data, data.GetType());
+            },
+            AppCacheProfile.Analytics,
+            [
+                AppCacheTags.Analytics,
+                AppCacheTags.BaseData,
+                AppCacheTags.Timetables
+            ],
+            cancellationToken);
+        return value;
+    }
+
+    private string StatisticsKey(
+        string area,
+        Guid? effectiveCollegeId,
+        params string?[] filters) =>
+        AppCacheKeys.Statistics(
+            area,
+            currentUser.Scope.ToString(),
+            effectiveCollegeId,
+            filters);
+
+    private static string KeyPart(Guid? value) =>
+        value?.ToString("N") ?? "-";
+
+    private static string KeyPart(int? value) =>
+        value?.ToString(System.Globalization.CultureInfo.InvariantCulture) ?? "-";
+
+    private static string KeyPart<TEnum>(TEnum? value)
+        where TEnum : struct, Enum =>
+        value?.ToString() ?? "-";
+
     private FileContentResult ExportSummary(
         string title,
         Dictionary<string, IEnumerable<object?[]>> sheets)

src/Jiaowu.Api/Controllers/SystemController.cs

@@ -0,0 +1,28 @@
+using System.Reflection;
+using Microsoft.AspNetCore.Authorization;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Jiaowu.Api.Controllers;
+
+[ApiController]
+[Route("api/system")]
+public sealed class SystemController : ControllerBase
+{
+    [AllowAnonymous]
+    [HttpGet("version")]
+    [ProducesResponseType<SystemVersionResponse>(StatusCodes.Status200OK)]
+    public SystemVersionResponse GetVersion()
+    {
+        var assembly = typeof(SystemController).Assembly;
+        var informationalVersion = assembly
+            .GetCustomAttribute<AssemblyInformationalVersionAttribute>()?
+            .InformationalVersion;
+        var version = informationalVersion?.Split('+', 2)[0]
+            ?? assembly.GetName().Version?.ToString(3)
+            ?? "unknown";
+
+        return new SystemVersionResponse(version);
+    }
+}
+
+public sealed record SystemVersionResponse(string Version);

src/Jiaowu.Api/Controllers/TeachingTasksController.cs

@@ -4,6 +4,7 @@ using Jiaowu.Api.Contracts;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
 using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.AspNetCore.Authorization;
@@ -17,7 +18,8 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/teaching-tasks")]
 public sealed class TeachingTasksController(
     AppDbContext db,
-    ICurrentUserDataScope currentUserDataScope) : ControllerBase
+    ICurrentUserDataScope currentUserDataScope,
+    IAppCache cache) : ControllerBase
 {
     private const string ManagementRoles =
         SystemRoles.SuperAdmin + "," +
@@ -80,6 +82,9 @@ public sealed class TeachingTasksController(
                 x.WeeklyHours,
                 x.SchedulingMode,
                 CourseTotalHours = x.Course.TotalHours,
+                CoursePracticeHours = x.Course.PracticeHours,
+                CourseRegularScheduleHours =
+                    x.Course.TotalHours - x.Course.PracticeHours,
                 x.GenerationBatchCode,
                 x.Status,
                 TeacherNames = x.Teachers
@@ -125,6 +130,10 @@ public sealed class TeachingTasksController(
                 x.EndWeek,
                 x.WeeklyHours,
                 x.SchedulingMode,
+                CourseTotalHours = x.Course!.TotalHours,
+                CoursePracticeHours = x.Course.PracticeHours,
+                CourseRegularScheduleHours =
+                    x.Course.TotalHours - x.Course.PracticeHours,
                 TeacherNames = x.Teachers
                     .OrderByDescending(item => item.IsPrimary)
                     .Select(item => item.Teacher!.Name),
@@ -161,6 +170,9 @@ public sealed class TeachingTasksController(
                 x.WeeklyHours,
                 x.SchedulingMode,
                 CourseTotalHours = x.Course.TotalHours,
+                CoursePracticeHours = x.Course.PracticeHours,
+                CourseRegularScheduleHours =
+                    x.Course.TotalHours - x.Course.PracticeHours,
                 x.GenerationBatchCode,
                 x.Status,
                 x.Notes,
@@ -389,6 +401,7 @@ public sealed class TeachingTasksController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
             return Ok(new { AffectedCount = tasks.Count });
         }
         catch (DbUpdateException)
@@ -420,7 +433,8 @@ public sealed class TeachingTasksController(
             course,
             request.StartWeek,
             request.EndWeek,
-            request.WeeklyHours);
+            request.WeeklyHours,
+            TeachingTaskSchedulingMode.Standard);
         if (hoursProblem is not null) return ValidationProblem(hoursProblem);
         if (course.Nature is not (CourseNature.GeneralRequired or CourseNature.GeneralElective))
             return ValidationProblem("批量合班生成仅用于公共必修课或公共选修课。");
@@ -544,6 +558,9 @@ public sealed class TeachingTasksController(
                 db.TeachingTasks.AddRange(created);
                 await db.SaveChangesAsync(cancellationToken);
                 await transaction.CommitAsync(cancellationToken);
+                await cache.RemoveByTagAsync(
+                    AppCacheTags.Timetables,
+                    cancellationToken);
                 return Ok(new
                 {
                     BatchCode = batchCode,
@@ -592,7 +609,8 @@ public sealed class TeachingTasksController(
             course,
             request.StartWeek,
             request.EndWeek,
-            request.WeeklyHours);
+            request.WeeklyHours,
+            request.SchedulingMode);
         if (hoursProblem is not null) return ValidationProblem(hoursProblem);
         var collegeId = ScopedCollegeId();
         if (!await db.AcademicTerms.AnyAsync(
@@ -737,6 +755,7 @@ public sealed class TeachingTasksController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
             return created ? Created(string.Empty, new { id }) : NoContent();
         }
         catch (DbUpdateException)

src/Jiaowu.Api/Controllers/TimetableManagementController.cs

@@ -209,7 +209,9 @@ public sealed class TimetableManagementController(
 
 [ApiController]
 [Route("api/timetables")]
-public sealed class FreeClassroomsController(AppDbContext db) : ControllerBase
+public sealed class FreeClassroomsController(
+    AppDbContext db,
+    ClassroomReservationAvailabilityService reservationAvailability) : ControllerBase
 {
     [HttpGet("free-classrooms/options")]
     [Authorize(Roles = SystemRoles.Student)]
@@ -297,9 +299,9 @@ public sealed class FreeClassroomsController(AppDbContext db) : ControllerBase
         CancellationToken cancellationToken = default)
     {
         var term = await db.AcademicTerms.AsNoTracking()
-            .Where(x => x.Id == academicTermId && x.IsEnabled)
+            .FirstOrDefaultAsync(
-            .Select(x => new { x.Id, x.Name })
+                x => x.Id == academicTermId && x.IsEnabled,
-            .FirstOrDefaultAsync(cancellationToken);
+                cancellationToken);
         if (term is null) return NotFound();
         var plan = await db.SchedulePlans.AsNoTracking()
             .Where(x =>
@@ -329,33 +331,17 @@ public sealed class FreeClassroomsController(AppDbContext db) : ControllerBase
         if (activePeriodCount != requestedPeriods.Length)
             return ValidationProblem("查询范围包含不存在或未启用的节次。");
 
-        var candidates = await db.ScheduleEntries.AsNoTracking()
+        var reservationDate = ResolveReservationDate(term, week, dayOfWeek);
-            .Where(x =>
+        if (reservationDate < term.StartDate || reservationDate > term.EndDate)
-                x.SchedulePlanId == plan.Id &&
+            return ValidationProblem("所选周次和星期不在学期日期范围内。");
-                x.ClassroomId.HasValue &&
+        var occupiedIds =
-                x.DayOfWeek == dayOfWeek &&
+            await reservationAvailability.GetOccupiedClassroomIdsAsync(
-                x.StartWeek <= week &&
+                term,
-                x.EndWeek >= week &&
+                reservationDate,
-                x.StartPeriod < startPeriod + periodCount &&
-                startPeriod < x.StartPeriod + x.PeriodCount)
-            .Select(x => new
-            {
-                x.ClassroomId,
-                x.WeekPattern,
-                x.StartPeriod,
-                x.PeriodCount
-            })
-            .ToListAsync(cancellationToken);
-        var occupiedIds = candidates
-            .Where(x =>
-                FreeClassroomRules.MatchesWeek(x.WeekPattern, week) &&
-                FreeClassroomRules.PeriodsOverlap(
                 startPeriod,
                 periodCount,
-                    x.StartPeriod,
+                null,
-                    x.PeriodCount))
+                cancellationToken);
-             .Select(x => x.ClassroomId.GetValueOrDefault())
-            .ToHashSet();
 
         var rooms = db.Classrooms.AsNoTracking()
             .Where(x =>
@@ -397,6 +383,17 @@ public sealed class FreeClassroomsController(AppDbContext db) : ControllerBase
         });
     }
 
+    private static DateOnly ResolveReservationDate(
+        AcademicTerm term,
+        int week,
+        int dayOfWeek)
+    {
+        var startDay = (int)term.StartDate.DayOfWeek;
+        var daysSinceMonday = (startDay + 6) % 7;
+        var firstWeekMonday = term.StartDate.AddDays(-daysSinceMonday);
+        return firstWeekMonday.AddDays((week - 1) * 7 + dayOfWeek - 1);
+    }
+
 }
 
 public sealed record FreeClassroomTimeSlotDto(

src/Jiaowu.Api/Controllers/TimetablesController.cs

@@ -1,6 +1,8 @@
 using System.Security.Claims;
+using System.Security.Cryptography;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Excel;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Timetables;
@@ -14,74 +16,25 @@ namespace Jiaowu.Api.Controllers;
 [Route("api/timetables")]
 public sealed class TimetablesController(
     AppDbContext db,
-    TimetableDataService timetableDataService) : ControllerBase
+    TimetableDataService timetableDataService,
+    PersonalCalendarService personalCalendarService,
+    IAppCache cache) : ControllerBase
 {
     [HttpGet("options")]
     [AllowAnonymous]
     public async Task<ActionResult> GetOptions(CancellationToken cancellationToken)
     {
-        var terms = await db.AcademicTerms.AsNoTracking()
+        var result = await cache.GetOrCreateAsync(
-            .Where(x => x.IsEnabled)
+            AppCacheKeys.TimetableOptions,
-            .OrderByDescending(x => x.StartDate)
+            LoadOptionsAsync,
-            .Select(x => new
+            AppCacheProfile.ReferenceData,
-            {
+            [
-                x.Id,
+                AppCacheTags.BaseData,
-                x.Name,
+                AppCacheTags.Timetables,
-                x.AcademicYear,
+                AppCacheTags.TimetableOptions
-                x.Season,
+            ],
-                x.StartDate,
+            cancellationToken);
-                x.EndDate,
+        return Ok(result);
-                x.IsCurrent,
-                x.IsArchived,
-                 HasPublishedTimetable = db.SchedulePlans.Any(plan =>
-                     plan.AcademicTermId == x.Id &&
-                     plan.Status == SchedulePlanStatus.Published) ||
-                     db.TeachingTasks.Any(task =>
-                         task.AcademicTermId == x.Id &&
-                         task.Status == TeachingTaskStatus.Published &&
-                         task.SchedulingMode == TeachingTaskSchedulingMode.Flexible)
-            })
-            .ToListAsync(cancellationToken);
-        var defaultTermId = terms.FirstOrDefault(x => x.IsCurrent)?.Id
-            ?? terms.FirstOrDefault(x => x.HasPublishedTimetable)?.Id;
-        var classes = await db.AdministrativeClasses.AsNoTracking()
-            .Where(x => x.IsEnabled && x.Major!.IsEnabled && x.Major.College!.IsEnabled)
-            .OrderByDescending(x => x.Grade)
-            .ThenBy(x => x.Code)
-            .Select(x => new
-            {
-                x.Id,
-                x.Code,
-                 x.Name,
-                 x.Grade,
-                 x.MajorId,
-                 MajorName = x.Major!.Name,
-                 CollegeId = x.Major.CollegeId,
-                 CollegeName = x.Major.College!.Name,
-                 HasPublishedTimetable = defaultTermId.HasValue &&
-                     (db.ScheduleEntries.Any(entry =>
-                          entry.SchedulePlan!.AcademicTermId == defaultTermId.Value &&
-                          entry.SchedulePlan.Status == SchedulePlanStatus.Published &&
-                          entry.TeachingTask!.Classes.Any(item =>
-                              item.AdministrativeClassId == x.Id)) ||
-                      db.TeachingTasks.Any(task =>
-                          task.AcademicTermId == defaultTermId.Value &&
-                          task.Status == TeachingTaskStatus.Published &&
-                          task.SchedulingMode == TeachingTaskSchedulingMode.Flexible &&
-                          task.Classes.Any(item => item.AdministrativeClassId == x.Id)))
-             })
-             .ToListAsync(cancellationToken);
-        var colleges = await db.Colleges.AsNoTracking()
-            .Where(x => x.IsEnabled)
-            .OrderBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name })
-            .ToListAsync(cancellationToken);
-        var majors = await db.Majors.AsNoTracking()
-            .Where(x => x.IsEnabled && x.College!.IsEnabled)
-            .OrderBy(x => x.Code)
-            .Select(x => new { x.Id, x.Code, x.Name, x.CollegeId })
-            .ToListAsync(cancellationToken);
-        return Ok(new { Terms = terms, Colleges = colleges, Majors = majors, Classes = classes });
     }
 
     [HttpGet("classes/{classId:guid}")]
@@ -99,14 +52,10 @@ public sealed class TimetablesController(
         Guid? academicTermId,
         CancellationToken cancellationToken)
     {
-        var result = await timetableDataService.BuildAsync(
+        var result = await GetPublishedTimetableAsync(
             TimetableResourceType.Teacher,
             teacherId,
             academicTermId,
-            null,
-            false,
-            null,
-            null,
             cancellationToken);
         return result is null ? NotFound() : Ok(result);
     }
@@ -118,14 +67,10 @@ public sealed class TimetablesController(
         Guid? academicTermId,
         CancellationToken cancellationToken)
     {
-        var result = await timetableDataService.BuildAsync(
+        var result = await GetPublishedTimetableAsync(
             TimetableResourceType.Teacher,
             teacherId,
             academicTermId,
-            null,
-            false,
-            null,
-            null,
             cancellationToken);
         if (result is null) return NotFound();
         return ExcelFile(result);
@@ -138,14 +83,10 @@ public sealed class TimetablesController(
         Guid? academicTermId,
         CancellationToken cancellationToken)
     {
-        var result = await timetableDataService.BuildAsync(
+        var result = await GetPublishedTimetableAsync(
             TimetableResourceType.Class,
             classId,
             academicTermId,
-            null,
-            false,
-            null,
-            null,
             cancellationToken);
         if (result is null) return NotFound();
         return ExcelFile(result);
@@ -262,6 +203,101 @@ public sealed class TimetablesController(
         return NotFound();
     }
 
+    [HttpGet("mine/calendar-subscription")]
+    [Authorize(Roles = SystemRoles.Student + "," + SystemRoles.Teacher)]
+    public async Task<ActionResult> GetMyCalendarSubscription(
+        CancellationToken cancellationToken)
+    {
+        var user = await CurrentUserAsync(cancellationToken);
+        if (user is null) return Unauthorized();
+        return Ok(BuildCalendarSubscriptionResponse(user));
+    }
+
+    [HttpPost("mine/calendar-subscription")]
+    [Authorize(Roles = SystemRoles.Student + "," + SystemRoles.Teacher)]
+    public async Task<ActionResult> EnableMyCalendarSubscription(
+        CancellationToken cancellationToken)
+    {
+        var user = await CurrentUserAsync(cancellationToken);
+        if (user is null) return Unauthorized();
+        if (string.IsNullOrWhiteSpace(user.CalendarSubscriptionStamp))
+        {
+            user.CalendarSubscriptionStamp = PersonalCalendarService.CreateStamp();
+            user.CalendarSubscriptionCreatedAt = DateTime.UtcNow;
+            await db.SaveChangesAsync(cancellationToken);
+        }
+        return Ok(BuildCalendarSubscriptionResponse(user));
+    }
+
+    [HttpPost("mine/calendar-subscription/rotate")]
+    [Authorize(Roles = SystemRoles.Student + "," + SystemRoles.Teacher)]
+    public async Task<ActionResult> RotateMyCalendarSubscription(
+        CancellationToken cancellationToken)
+    {
+        var user = await CurrentUserAsync(cancellationToken);
+        if (user is null) return Unauthorized();
+        user.CalendarSubscriptionStamp = PersonalCalendarService.CreateStamp();
+        user.CalendarSubscriptionCreatedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(cancellationToken);
+        return Ok(BuildCalendarSubscriptionResponse(user));
+    }
+
+    [HttpDelete("mine/calendar-subscription")]
+    [Authorize(Roles = SystemRoles.Student + "," + SystemRoles.Teacher)]
+    public async Task<ActionResult> DisableMyCalendarSubscription(
+        CancellationToken cancellationToken)
+    {
+        var user = await CurrentUserAsync(cancellationToken);
+        if (user is null) return Unauthorized();
+        user.CalendarSubscriptionStamp = null;
+        user.CalendarSubscriptionCreatedAt = null;
+        await db.SaveChangesAsync(cancellationToken);
+        return NoContent();
+    }
+
+    [HttpGet("mine/calendar.ics")]
+    [Authorize(Roles = SystemRoles.Student + "," + SystemRoles.Teacher)]
+    public async Task<ActionResult> DownloadMyCalendar(
+        CancellationToken cancellationToken)
+    {
+        var user = await CurrentUserAsync(cancellationToken);
+        if (user is null) return Unauthorized();
+        var result = await personalCalendarService.BuildAsync(user, cancellationToken);
+        if (result is null) return CalendarProfileNotFound();
+        return File(
+            result.Content,
+            "text/calendar; charset=utf-8",
+            $"{SafeFileName(user.DisplayName)}-个人教学日历.ics");
+    }
+
+    [HttpGet("calendar/{userId:guid}/{accessToken}.ics")]
+    [AllowAnonymous]
+    public async Task<ActionResult> GetCalendarFeed(
+        Guid userId,
+        string accessToken,
+        CancellationToken cancellationToken)
+    {
+        var user = await db.Users.AsNoTracking()
+            .FirstOrDefaultAsync(x => x.Id == userId, cancellationToken);
+        if (user is null ||
+            !personalCalendarService.IsAccessTokenValid(user, accessToken))
+            return NotFound();
+
+        var result = await personalCalendarService.BuildAsync(user, cancellationToken);
+        if (result is null) return NotFound();
+        var etag = $"\"{Convert.ToHexString(SHA256.HashData(result.Content))}\"";
+        if (Request.Headers.IfNoneMatch.ToString()
+            .Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries)
+            .Contains(etag, StringComparer.Ordinal))
+        {
+            return StatusCode(StatusCodes.Status304NotModified);
+        }
+        Response.Headers.CacheControl = "private, max-age=300";
+        Response.Headers.ETag = etag;
+        Response.Headers.Append("X-Content-Type-Options", "nosniff");
+        return File(result.Content, "text/calendar; charset=utf-8");
+    }
+
     private async Task<ActionResult> BuildTimetableAsync(
         Guid classId,
         Guid? academicTermId,
@@ -269,7 +305,8 @@ public sealed class TimetablesController(
         CancellationToken cancellationToken,
         TimetableStudentDto? student = null)
     {
-        var result = await timetableDataService.BuildAsync(
+        var result = studentId.HasValue || student is not null
+            ? await timetableDataService.BuildAsync(
                 TimetableResourceType.Class,
                 classId,
                 academicTermId,
@@ -277,10 +314,110 @@ public sealed class TimetablesController(
                 false,
                 studentId,
                 student,
+                cancellationToken)
+            : await GetPublishedTimetableAsync(
+                TimetableResourceType.Class,
+                classId,
+                academicTermId,
                 cancellationToken);
          return result is null ? NotFound() : Ok(result);
      }
 
+    private Task<TimetableData?> GetPublishedTimetableAsync(
+        TimetableResourceType resourceType,
+        Guid resourceId,
+        Guid? academicTermId,
+        CancellationToken cancellationToken) =>
+        cache.GetOrCreateAsync(
+            AppCacheKeys.PublishedTimetable(
+                resourceType.ToString().ToLowerInvariant(),
+                resourceId,
+                academicTermId),
+            token => timetableDataService.BuildAsync(
+                resourceType,
+                resourceId,
+                academicTermId,
+                null,
+                false,
+                null,
+                null,
+                token),
+            AppCacheProfile.PublishedTimetable,
+            [AppCacheTags.BaseData, AppCacheTags.Timetables],
+            cancellationToken);
+
+    private async Task<TimetableOptionsResponse> LoadOptionsAsync(
+        CancellationToken cancellationToken)
+    {
+        var terms = await db.AcademicTerms.AsNoTracking()
+            .Where(x => x.IsEnabled)
+            .OrderByDescending(x => x.StartDate)
+            .Select(x => new TimetableTermOption(
+                x.Id,
+                x.Name,
+                x.AcademicYear,
+                x.Season,
+                x.StartDate,
+                x.EndDate,
+                x.IsCurrent,
+                x.IsArchived,
+                db.SchedulePlans.Any(plan =>
+                    plan.AcademicTermId == x.Id &&
+                    plan.Status == SchedulePlanStatus.Published) ||
+                db.TeachingTasks.Any(task =>
+                    task.AcademicTermId == x.Id &&
+                    task.Status == TeachingTaskStatus.Published &&
+                    task.SchedulingMode == TeachingTaskSchedulingMode.Flexible) ||
+                db.ExamPlans.Any(plan =>
+                    plan.AcademicTermId == x.Id &&
+                    plan.Status == ExamPlanStatus.Published)))
+            .ToListAsync(cancellationToken);
+        var defaultTermId = terms.FirstOrDefault(x => x.IsCurrent)?.Id
+            ?? terms.FirstOrDefault(x => x.HasPublishedTimetable)?.Id;
+        var classes = await db.AdministrativeClasses.AsNoTracking()
+            .Where(x => x.IsEnabled && x.Major!.IsEnabled && x.Major.College!.IsEnabled)
+            .OrderByDescending(x => x.Grade)
+            .ThenBy(x => x.Code)
+            .Select(x => new TimetableClassOption(
+                x.Id,
+                x.Code,
+                x.Name,
+                x.Grade,
+                x.MajorId,
+                x.Major!.Name,
+                x.Major.CollegeId,
+                x.Major.College!.Name,
+                defaultTermId.HasValue &&
+                (db.ScheduleEntries.Any(entry =>
+                     entry.SchedulePlan!.AcademicTermId == defaultTermId.Value &&
+                     entry.SchedulePlan.Status == SchedulePlanStatus.Published &&
+                     entry.TeachingTask!.Classes.Any(item =>
+                         item.AdministrativeClassId == x.Id)) ||
+                 db.TeachingTasks.Any(task =>
+                     task.AcademicTermId == defaultTermId.Value &&
+                     task.Status == TeachingTaskStatus.Published &&
+                     task.SchedulingMode == TeachingTaskSchedulingMode.Flexible &&
+                     task.Classes.Any(item => item.AdministrativeClassId == x.Id)) ||
+                 db.ExamSessions.Any(session =>
+                     session.ExamPlan!.AcademicTermId == defaultTermId.Value &&
+                     session.ExamPlan.Status == ExamPlanStatus.Published &&
+                     session.TeachingTask!.Classes.Any(item =>
+                         item.AdministrativeClassId == x.Id)))))
+            .ToListAsync(cancellationToken);
+        var colleges = await db.Colleges.AsNoTracking()
+            .Where(x => x.IsEnabled)
+            .OrderBy(x => x.Code)
+            .Select(x => new TimetableCollegeOption(x.Id, x.Code, x.Name))
+            .ToListAsync(cancellationToken);
+        var majors = await db.Majors.AsNoTracking()
+            .Where(x => x.IsEnabled && x.College!.IsEnabled)
+            .OrderBy(x => x.Code)
+            .Select(x => new TimetableMajorOption(
+                x.Id, x.Code, x.Name, x.CollegeId))
+            .ToListAsync(cancellationToken);
+        return new TimetableOptionsResponse(terms, colleges, majors, classes);
+    }
+
     private ActionResult ExcelFile(TimetableData result)
     {
         var bytes = TimetableExcelExporter.Create(result);
@@ -295,4 +432,89 @@ public sealed class TimetablesController(
             value = value.Replace(character, '-');
         return value.Trim();
     }
+
+    private async Task<ApplicationUser?> CurrentUserAsync(
+        CancellationToken cancellationToken)
+    {
+        if (!Guid.TryParse(User.FindFirstValue(ClaimTypes.NameIdentifier), out var userId))
+            return null;
+        return await db.Users.FirstOrDefaultAsync(
+            x => x.Id == userId && x.IsEnabled,
+            cancellationToken);
     }
+
+    private PersonalCalendarSubscriptionResponse BuildCalendarSubscriptionResponse(
+        ApplicationUser user)
+    {
+        if (string.IsNullOrWhiteSpace(user.CalendarSubscriptionStamp))
+            return new(false, null, null, null, null);
+
+        var accessToken = personalCalendarService.CreateAccessToken(user);
+        var feedPath =
+            $"timetables/calendar/{user.Id:N}/{accessToken}.ics";
+        var feedUrl =
+            $"{Request.Scheme}://{Request.Host}{Request.PathBase}" +
+            $"/api/{feedPath}";
+        var webcalUrl = feedUrl.StartsWith("https://", StringComparison.OrdinalIgnoreCase)
+            ? $"webcal://{feedUrl[8..]}"
+            : feedUrl.StartsWith("http://", StringComparison.OrdinalIgnoreCase)
+                ? $"webcal://{feedUrl[7..]}"
+                : feedUrl;
+        return new(
+            true,
+            feedUrl,
+            feedPath,
+            webcalUrl,
+            user.CalendarSubscriptionCreatedAt);
+    }
+
+    private ActionResult CalendarProfileNotFound() => Conflict(new ProblemDetails
+    {
+        Title = "档案未关联",
+        Detail = "当前登录账号没有关联有效的教师或学生档案，请联系教务管理员。",
+        Status = StatusCodes.Status409Conflict
+    });
+}
+
+public sealed record PersonalCalendarSubscriptionResponse(
+    bool IsEnabled,
+    string? FeedUrl,
+    string? FeedPath,
+    string? WebcalUrl,
+    DateTime? CreatedAt);
+
+public sealed record TimetableOptionsResponse(
+    IReadOnlyList<TimetableTermOption> Terms,
+    IReadOnlyList<TimetableCollegeOption> Colleges,
+    IReadOnlyList<TimetableMajorOption> Majors,
+    IReadOnlyList<TimetableClassOption> Classes);
+
+public sealed record TimetableTermOption(
+    Guid Id,
+    string Name,
+    string AcademicYear,
+    TermSeason Season,
+    DateOnly StartDate,
+    DateOnly EndDate,
+    bool IsCurrent,
+    bool IsArchived,
+    bool HasPublishedTimetable);
+
+public sealed record TimetableCollegeOption(Guid Id, string Code, string Name);
+
+public sealed record TimetableMajorOption(
+    Guid Id,
+    string Code,
+    string Name,
+    Guid CollegeId);
+
+public sealed record TimetableClassOption(
+    Guid Id,
+    string Code,
+    string Name,
+    int Grade,
+    Guid MajorId,
+    string MajorName,
+    Guid CollegeId,
+    string CollegeName,
+    bool HasPublishedTimetable);

src/Jiaowu.Api/Controllers/WarningsController.cs

@@ -92,12 +92,12 @@ public sealed class WarningsController(AppDbContext db, ICurrentUserDataScope sc
                 var si = studentInfos.First(s => s.Id == w.StudentId);
                 var r = rules.First(r => r.Type == w.Type);
                 if (r.NotifyStudent && si.UserId.HasValue)
-                    await NotificationService.SendAsync(db, si.UserId.Value, "学业预警", w.Detail, "/warnings", cancellationToken: ct);
+                    await NotificationService.SendAsync(db, si.UserId.Value, "学业预警", w.Detail, "/warnings", ct, NotificationCategory.Warning);
                 if (r.NotifyCounselor)
                 {
                     var counselorId = await db.AdministrativeClasses.Where(c => c.Id == si.ClassId && c.CounselorUserId != null).Select(c => c.CounselorUserId!.Value).FirstOrDefaultAsync(ct);
                     if (counselorId != default)
-                        await NotificationService.SendAsync(db, counselorId, "学生学业预警", $"{si.Name}：{w.Detail}", "/warnings", cancellationToken: ct);
+                        await NotificationService.SendAsync(db, counselorId, "学生学业预警", $"{si.Name}：{w.Detail}", "/warnings", ct, NotificationCategory.Warning);
                 }
             }
         }

src/Jiaowu.Api/Domain/Academic/AttendanceEntities.cs

@@ -20,6 +20,7 @@ public sealed class AttendanceSheet : EntityBase
     public string? Notes { get; set; }
     public DateTime? SubmittedAt { get; set; }
     public ICollection<AttendanceRecord> Records { get; set; } = [];
+    public ICollection<AttendanceCheckInAttempt> CheckInAttempts { get; set; } = [];
 }
 
 public sealed class AttendanceRecord
@@ -43,6 +44,26 @@ public sealed class AttendanceRecord
     public DateTime? AppealReviewedAt { get; set; }
 }
 
+public sealed class AttendanceCheckInAttempt : EntityBase
+{
+    public Guid AttendanceSheetId { get; set; }
+    public AttendanceSheet? AttendanceSheet { get; set; }
+    public Guid StudentId { get; set; }
+    public Student? Student { get; set; }
+    public AttendanceCheckInMethod CheckInMethod { get; set; }
+    public bool IsSuccessful { get; set; }
+    public string? FailureCode { get; set; }
+    public string? DeviceIdentifierHash { get; set; }
+    public string? DevicePlatform { get; set; }
+    public string? IpAddress { get; set; }
+    public string? UserAgent { get; set; }
+    public string? RiskFlags { get; set; }
+    public decimal? Latitude { get; set; }
+    public decimal? Longitude { get; set; }
+    public double? AccuracyMeters { get; set; }
+    public double? DistanceMeters { get; set; }
+}
+
 public enum AttendanceSheetStatus
 {
     Draft = 1,

src/Jiaowu.Api/Domain/Academic/ClassroomReservationEntities.cs

@@ -0,0 +1,39 @@
+using Jiaowu.Api.Domain.Common;
+using Jiaowu.Api.Domain.Identity;
+
+namespace Jiaowu.Api.Domain.Academic;
+
+public sealed class ClassroomReservation : EntityBase
+{
+    public Guid ApplicantUserId { get; set; }
+    public ApplicationUser? ApplicantUser { get; set; }
+    public required string ApplicantName { get; set; }
+    public Guid ApplicantCollegeId { get; set; }
+    public College? ApplicantCollege { get; set; }
+    public Guid AcademicTermId { get; set; }
+    public AcademicTerm? AcademicTerm { get; set; }
+    public Guid ClassroomId { get; set; }
+    public Classroom? Classroom { get; set; }
+    public DateOnly ReservationDate { get; set; }
+    public int StartPeriod { get; set; }
+    public int PeriodCount { get; set; }
+    public int AttendeeCount { get; set; }
+    public required string Purpose { get; set; }
+    public required string ContactPhone { get; set; }
+    public string? Notes { get; set; }
+    public ClassroomReservationStatus Status { get; set; } =
+        ClassroomReservationStatus.Submitted;
+    public Guid? ReviewedByUserId { get; set; }
+    public ApplicationUser? ReviewedByUser { get; set; }
+    public DateTime? ReviewedAt { get; set; }
+    public string? ReviewComment { get; set; }
+    public DateTime? CancelledAt { get; set; }
+}
+
+public enum ClassroomReservationStatus
+{
+    Submitted = 1,
+    Approved = 2,
+    Rejected = 3,
+    Cancelled = 4
+}

src/Jiaowu.Api/Domain/Academic/CourseAdjustmentEntities.cs

@@ -10,7 +10,15 @@ public sealed class CourseAdjustment : EntityBase
     public CourseAdjustmentStatus Status { get; set; } = CourseAdjustmentStatus.Draft;
     public Guid ApplicantUserId { get; set; }
 
-    // For Reschedule / Makeup
+    // The concrete published timetable occurrence being adjusted.
+    public Guid? SourceScheduleEntryId { get; set; }
+    public int? SourceWeek { get; set; }
+    public DateOnly? SourceDate { get; set; }
+    public int? SourceStartPeriod { get; set; }
+    public int? SourcePeriodCount { get; set; }
+    public Guid? SourceClassroomId { get; set; }
+
+    // Target occurrence for Reschedule / Makeup
     public DateOnly? TargetDate { get; set; }
     public int? DayOfWeek { get; set; }
     public int? StartPeriod { get; set; }

src/Jiaowu.Api/Domain/Academic/CourseSelectionEntities.cs

@@ -11,12 +11,21 @@ public sealed class CourseSelectionRound : EntityBase
     public DateTime EndsAt { get; set; }
     public DateTime WithdrawalEndsAt { get; set; }
     public decimal MaxCredits { get; set; } = 30;
+    public int? MaxCourseCount { get; set; }
     public CourseSelectionRoundStatus Status { get; set; } =
         CourseSelectionRoundStatus.Draft;
     public string? Notes { get; set; }
+    public ICollection<CourseSelectionRoundGrade> EligibleGrades { get; set; } = [];
     public ICollection<CourseSelectionOffering> Offerings { get; set; } = [];
 }
 
+public sealed class CourseSelectionRoundGrade : EntityBase
+{
+    public Guid CourseSelectionRoundId { get; set; }
+    public CourseSelectionRound? CourseSelectionRound { get; set; }
+    public int Grade { get; set; }
+}
+
 public sealed class CourseSelectionOffering : EntityBase
 {
     public Guid CourseSelectionRoundId { get; set; }
@@ -38,6 +47,7 @@ public sealed class CourseEnrollment : EntityBase
     public CourseEnrollmentStatus Status { get; set; } = CourseEnrollmentStatus.Enrolled;
     public EnrollmentType EnrollmentType { get; set; } = EnrollmentType.Normal;
     public DateTime EnrolledAt { get; set; } = DateTime.UtcNow;
+    public DateTime? WaitlistedAt { get; set; }
     public DateTime? WithdrawnAt { get; set; }
 }
 
@@ -51,7 +61,10 @@ public enum CourseSelectionRoundStatus
 public enum CourseEnrollmentStatus
 {
     Enrolled = 1,
-    Withdrawn = 2
+    Withdrawn = 2,
+    Waitlisted = 3,
+    Cancelled = 4,
+    Expired = 5
 }
 
 public enum EnrollmentType

src/Jiaowu.Api/Domain/Academic/ExamEntities.cs

@@ -11,6 +11,41 @@ public sealed class ExamPlan : EntityBase
     public string? Notes { get; set; }
     public DateTime? PublishedAt { get; set; }
     public ICollection<ExamSession> Sessions { get; set; } = [];
+    public ICollection<ExamRoomAssignment> Rooms { get; set; } = [];
+}
+
+public sealed class ExamArrangementJob : EntityBase
+{
+    public ExamArrangementKind Kind { get; set; }
+    public Guid PlanId { get; set; }
+    public Guid? ActivePlanId { get; set; }
+    public Guid? RequestedByUserId { get; set; }
+    public string? SessionIdsJson { get; set; }
+    public bool AssignClassrooms { get; set; }
+    public bool AssignInvigilators { get; set; }
+    public ExamArrangementJobStatus Status { get; set; } =
+        ExamArrangementJobStatus.Queued;
+    public int TotalSessions { get; set; }
+    public int ProcessedSessions { get; set; }
+    public string? CurrentStep { get; set; }
+    public string? ResultMessage { get; set; }
+    public string? ErrorMessage { get; set; }
+    public DateTime? StartedAt { get; set; }
+    public DateTime? CompletedAt { get; set; }
+}
+
+public enum ExamArrangementKind
+{
+    FormalExam = 1,
+    MakeupExam = 2
+}
+
+public enum ExamArrangementJobStatus
+{
+    Queued = 1,
+    Running = 2,
+    Succeeded = 3,
+    Failed = 4
 }
 
 public sealed class ExamSession : EntityBase
@@ -28,9 +63,12 @@ public sealed class ExamSession : EntityBase
     public DateTime EndsAt { get; set; }
     public Guid? RequiredBuildingId { get; set; }
     public Building? RequiredBuilding { get; set; }
+    public string? RequiredBuildingIds { get; set; }
     public int RequiredInvigilatorCount { get; set; } = 2;
     public string? Notes { get; set; }
     public ICollection<ExamSessionInvigilator> Invigilators { get; set; } = [];
+    public ICollection<ExamRoomSession> RoomLinks { get; set; } = [];
+    public ICollection<ExamSeatAssignment> SeatAssignments { get; set; } = [];
 }
 
 public sealed class ExamSessionInvigilator
@@ -41,9 +79,82 @@ public sealed class ExamSessionInvigilator
     public Teacher? Teacher { get; set; }
 }
 
+public sealed class ExamRoomAssignment : EntityBase
+{
+    public Guid ExamPlanId { get; set; }
+    public ExamPlan? ExamPlan { get; set; }
+    public Guid CourseId { get; set; }
+    public Course? Course { get; set; }
+    public Guid ClassroomId { get; set; }
+    public Classroom? Classroom { get; set; }
+    public DateOnly ExamDate { get; set; }
+    public int StartPeriod { get; set; }
+    public int PeriodCount { get; set; }
+    public DateTime StartsAt { get; set; }
+    public DateTime EndsAt { get; set; }
+    public int RequiredInvigilatorCount { get; set; } = 2;
+    public ICollection<ExamRoomSession> SessionLinks { get; set; } = [];
+    public ICollection<ExamSeatAssignment> Seats { get; set; } = [];
+    public ICollection<ExamRoomInvigilator> Invigilators { get; set; } = [];
+}
+
+public sealed class ExamRoomSession
+{
+    public Guid ExamRoomId { get; set; }
+    public ExamRoomAssignment? ExamRoom { get; set; }
+    public Guid ExamSessionId { get; set; }
+    public ExamSession? ExamSession { get; set; }
+}
+
+public sealed class ExamSeatAssignment
+{
+    public Guid ExamRoomId { get; set; }
+    public ExamRoomAssignment? ExamRoom { get; set; }
+    public Guid ExamSessionId { get; set; }
+    public ExamSession? ExamSession { get; set; }
+    public Guid StudentId { get; set; }
+    public Student? Student { get; set; }
+    public int SeatNumber { get; set; }
+}
+
+public sealed class ExamRoomInvigilator
+{
+    public Guid ExamRoomId { get; set; }
+    public ExamRoomAssignment? ExamRoom { get; set; }
+    public Guid TeacherId { get; set; }
+    public Teacher? Teacher { get; set; }
+}
+
 public enum ExamPlanStatus
 {
     Draft = 1,
     Published = 2,
     Archived = 3
 }
+
+public sealed class ExamPublishJob : EntityBase
+{
+    public ExamPublishJobKind Kind { get; set; }
+    public Guid PlanId { get; set; }
+    public Guid? ActivePlanId { get; set; }
+    public Guid? RequestedByUserId { get; set; }
+    public ExamPublishJobStatus Status { get; set; } = ExamPublishJobStatus.Queued;
+    public string? CurrentStep { get; set; }
+    public string? ErrorMessage { get; set; }
+    public DateTime? StartedAt { get; set; }
+    public DateTime? CompletedAt { get; set; }
+}
+
+public enum ExamPublishJobKind
+{
+    FormalExam = 1,
+    MakeupExam = 2
+}
+
+public enum ExamPublishJobStatus
+{
+    Queued = 1,
+    Running = 2,
+    Succeeded = 3,
+    Failed = 4
+}

src/Jiaowu.Api/Domain/Academic/ExamSignInExportJob.cs

@@ -0,0 +1,26 @@
+using Jiaowu.Api.Domain.Common;
+
+namespace Jiaowu.Api.Domain.Academic;
+
+public sealed class ExamSignInExportJob : EntityBase
+{
+    public Guid PlanId { get; set; }
+    public ExamSignInExportJobStatus Status { get; set; } =
+        ExamSignInExportJobStatus.Queued;
+    public Guid? RequestedByUserId { get; set; }
+    public string? FileName { get; set; }
+    public byte[]? FileBytes { get; set; }
+    public int FileSize { get; set; }
+    public string? CurrentStep { get; set; }
+    public string? ErrorMessage { get; set; }
+    public DateTime? StartedAt { get; set; }
+    public DateTime? CompletedAt { get; set; }
+}
+
+public enum ExamSignInExportJobStatus
+{
+    Queued = 1,
+    Running = 2,
+    Succeeded = 3,
+    Failed = 4
+}

src/Jiaowu.Api/Domain/Academic/ExperimentEntities.cs

@@ -0,0 +1,80 @@
+using Jiaowu.Api.Domain.Common;
+
+namespace Jiaowu.Api.Domain.Academic;
+
+public sealed class ExperimentProject : EntityBase
+{
+    public Guid TeachingTaskId { get; set; }
+    public TeachingTask? TeachingTask { get; set; }
+    public required string Code { get; set; }
+    public required string Name { get; set; }
+    public ExperimentArrangementMode ArrangementMode { get; set; }
+    public string? Description { get; set; }
+    public string? Requirements { get; set; }
+    public DateOnly StartDate { get; set; }
+    public DateOnly EndDate { get; set; }
+    public ExperimentProjectStatus Status { get; set; } =
+        ExperimentProjectStatus.Draft;
+    public DateTime? PublishedAt { get; set; }
+    public DateTime? ClosedAt { get; set; }
+    public ICollection<ExperimentSession> Sessions { get; set; } = [];
+    public ICollection<ExperimentBooking> Bookings { get; set; } = [];
+    public ExperimentGradeSheet? GradeSheet { get; set; }
+}
+
+public sealed class ExperimentSession : EntityBase
+{
+    public Guid ExperimentProjectId { get; set; }
+    public ExperimentProject? ExperimentProject { get; set; }
+    public Guid ClassroomId { get; set; }
+    public Classroom? Classroom { get; set; }
+    public DateOnly SessionDate { get; set; }
+    public int StartPeriod { get; set; }
+    public int PeriodCount { get; set; }
+    public int Capacity { get; set; }
+    public int ReservedCount { get; set; }
+    public string? Notes { get; set; }
+    public ExperimentSessionStatus Status { get; set; } =
+        ExperimentSessionStatus.Scheduled;
+    public DateTime? CancelledAt { get; set; }
+    public ICollection<ExperimentBooking> Bookings { get; set; } = [];
+}
+
+public sealed class ExperimentBooking : EntityBase
+{
+    public Guid ExperimentProjectId { get; set; }
+    public ExperimentProject? ExperimentProject { get; set; }
+    public Guid ExperimentSessionId { get; set; }
+    public ExperimentSession? ExperimentSession { get; set; }
+    public Guid StudentId { get; set; }
+    public Student? Student { get; set; }
+    public ExperimentBookingStatus Status { get; set; } =
+        ExperimentBookingStatus.Booked;
+    public DateTime BookedAt { get; set; } = DateTime.UtcNow;
+    public DateTime? CancelledAt { get; set; }
+}
+
+public enum ExperimentArrangementMode
+{
+    Centralized = 1,
+    SelfScheduled = 2
+}
+
+public enum ExperimentProjectStatus
+{
+    Draft = 1,
+    Published = 2,
+    Closed = 3
+}
+
+public enum ExperimentSessionStatus
+{
+    Scheduled = 1,
+    Cancelled = 2
+}
+
+public enum ExperimentBookingStatus
+{
+    Booked = 1,
+    Cancelled = 2
+}

src/Jiaowu.Api/Domain/Academic/ExperimentGradeEntities.cs

@@ -0,0 +1,92 @@
+using Jiaowu.Api.Domain.Common;
+
+namespace Jiaowu.Api.Domain.Academic;
+
+public sealed class ExperimentGradeSheet : EntityBase
+{
+    public Guid ExperimentProjectId { get; set; }
+    public ExperimentProject? ExperimentProject { get; set; }
+    public decimal ContributionWeight { get; set; } = 1;
+    public decimal PassScore { get; set; } = 60;
+    public ExperimentGradeSheetStatus Status { get; set; } =
+        ExperimentGradeSheetStatus.Draft;
+    public string? ReviewComment { get; set; }
+    public DateTime? SubmittedAt { get; set; }
+    public DateTime? ReviewedAt { get; set; }
+    public DateTime? PublishedAt { get; set; }
+    public ICollection<ExperimentGradeItem> Items { get; set; } = [];
+    public ICollection<ExperimentGradeRecord> Records { get; set; } = [];
+}
+
+public sealed class ExperimentGradeItem : EntityBase
+{
+    public Guid ExperimentGradeSheetId { get; set; }
+    public ExperimentGradeSheet? ExperimentGradeSheet { get; set; }
+    public required string Name { get; set; }
+    public ExperimentGradeItemKind Kind { get; set; } =
+        ExperimentGradeItemKind.Other;
+    public decimal Weight { get; set; }
+    public int SortOrder { get; set; }
+    public ICollection<ExperimentGradeItemScore> Scores { get; set; } = [];
+}
+
+public sealed class ExperimentGradeRecord : EntityBase
+{
+    public Guid ExperimentGradeSheetId { get; set; }
+    public ExperimentGradeSheet? ExperimentGradeSheet { get; set; }
+    public Guid StudentId { get; set; }
+    public Student? Student { get; set; }
+    public Guid? ExperimentSessionId { get; set; }
+    public ExperimentSession? ExperimentSession { get; set; }
+    public ExperimentParticipationStatus ParticipationStatus { get; set; } =
+        ExperimentParticipationStatus.Pending;
+    public decimal? TotalScore { get; set; }
+    public bool? IsPassed { get; set; }
+    public bool SafetyViolation { get; set; }
+    public int AttemptNumber { get; set; } = 1;
+    public string? SubmissionReference { get; set; }
+    public DateTime? SubmittedAt { get; set; }
+    public bool IsLate { get; set; }
+    public string? TeacherComment { get; set; }
+    public ICollection<ExperimentGradeItemScore> ItemScores { get; set; } = [];
+}
+
+public sealed class ExperimentGradeItemScore
+{
+    public Guid ExperimentGradeRecordId { get; set; }
+    public ExperimentGradeRecord? ExperimentGradeRecord { get; set; }
+    public Guid ExperimentGradeItemId { get; set; }
+    public ExperimentGradeItem? ExperimentGradeItem { get; set; }
+    public decimal? Score { get; set; }
+    public string? Comment { get; set; }
+}
+
+public enum ExperimentGradeSheetStatus
+{
+    Draft = 1,
+    Submitted = 2,
+    Approved = 3,
+    Published = 4,
+    Returned = 5
+}
+
+public enum ExperimentGradeItemKind
+{
+    Operation = 1,
+    Report = 2,
+    Result = 3,
+    Defense = 4,
+    Attendance = 5,
+    Safety = 6,
+    Other = 7
+}
+
+public enum ExperimentParticipationStatus
+{
+    Pending = 1,
+    Completed = 2,
+    Absent = 3,
+    Excused = 4,
+    Makeup = 5,
+    Exempt = 6
+}

src/Jiaowu.Api/Domain/Academic/GradeEntities.cs

@@ -24,6 +24,9 @@ public sealed class GradeItem : EntityBase
     public required string Name { get; set; }
     public decimal Weight { get; set; }
     public int SortOrder { get; set; }
+    public GradeItemSourceType SourceType { get; set; } =
+        GradeItemSourceType.Manual;
+    public DateTime? SourceSnapshotAt { get; set; }
     public ICollection<GradeItemScore> Scores { get; set; } = [];
 }
 
@@ -68,3 +71,9 @@ public enum GradeExamStatus
     Exempt = 4,
     Makeup = 5
 }
+
+public enum GradeItemSourceType
+{
+    Manual = 1,
+    ExperimentSummary = 2
+}

src/Jiaowu.Api/Domain/Academic/MakeupExamEntities.cs

@@ -28,6 +28,7 @@ public sealed class MakeupExamSession : EntityBase
     public DateTime EndsAt { get; set; }
     public Guid? RequiredBuildingId { get; set; }
     public Building? RequiredBuilding { get; set; }
+    public string? RequiredBuildingIds { get; set; }
     public int RequiredInvigilatorCount { get; set; } = 2;
     public string? Notes { get; set; }
     public ICollection<MakeupExamSessionInvigilator> Invigilators { get; set; } = [];

src/Jiaowu.Api/Domain/Academic/NotificationEntities.cs

@@ -7,6 +7,43 @@ public sealed class Notification : EntityBase
     public Guid UserId { get; set; }
     public required string Title { get; set; }
     public required string Content { get; set; }
+    public NotificationCategory Category { get; set; } = NotificationCategory.General;
     public bool IsRead { get; set; }
     public string? LinkUrl { get; set; }
+    public Guid? MessageDispatchId { get; set; }
+    public MessageDispatch? MessageDispatch { get; set; }
+}
+
+public sealed class MessageDispatch : EntityBase
+{
+    public Guid SenderUserId { get; set; }
+    public required string SenderName { get; set; }
+    public required string Title { get; set; }
+    public required string Content { get; set; }
+    public NotificationCategory Category { get; set; } = NotificationCategory.General;
+    public MessageAudienceType AudienceType { get; set; }
+    public Guid? AudienceId { get; set; }
+    public required string AudienceName { get; set; }
+    public int RecipientCount { get; set; }
+    public string? LinkUrl { get; set; }
+    public ICollection<Notification> Notifications { get; set; } = [];
+}
+
+public enum NotificationCategory
+{
+    General = 1,
+    Approval = 2,
+    Schedule = 3,
+    Grade = 4,
+    Attendance = 5,
+    CourseSelection = 6,
+    Warning = 7
+}
+
+public enum MessageAudienceType
+{
+    School = 1,
+    College = 2,
+    TeachingTask = 3,
+    Custom = 4
 }

src/Jiaowu.Api/Domain/Academic/OfficialDocumentEntities.cs

@@ -0,0 +1,51 @@
+using Jiaowu.Api.Domain.Common;
+using Jiaowu.Api.Domain.Identity;
+
+namespace Jiaowu.Api.Domain.Academic;
+
+public sealed class OfficialDocument : EntityBase
+{
+    public required string DocumentNumber { get; set; }
+    public required string VerificationCodeHash { get; set; }
+    public OfficialDocumentType Type { get; set; }
+    public OfficialDocumentStatus Status { get; set; } = OfficialDocumentStatus.Valid;
+    public Guid StudentId { get; set; }
+    public Student? Student { get; set; }
+    public Guid IssuedByUserId { get; set; }
+    public ApplicationUser? IssuedByUser { get; set; }
+    public DateTime IssuedAt { get; set; } = DateTime.UtcNow;
+    public string? Purpose { get; set; }
+    public required string SnapshotJson { get; set; }
+    public required byte[] PdfContent { get; set; }
+    public required string PdfSha256 { get; set; }
+    public DateTime? InvalidatedAt { get; set; }
+    public Guid? InvalidatedByUserId { get; set; }
+    public ApplicationUser? InvalidatedByUser { get; set; }
+    public string? InvalidationReason { get; set; }
+    public Guid? ReissuedFromDocumentId { get; set; }
+    public OfficialDocument? ReissuedFromDocument { get; set; }
+    public ICollection<OfficialDocumentDownload> Downloads { get; set; } = [];
+}
+
+public sealed class OfficialDocumentDownload : EntityBase
+{
+    public Guid OfficialDocumentId { get; set; }
+    public OfficialDocument? OfficialDocument { get; set; }
+    public Guid DownloadedByUserId { get; set; }
+    public ApplicationUser? DownloadedByUser { get; set; }
+    public string? IpAddress { get; set; }
+    public string? UserAgent { get; set; }
+}
+
+public enum OfficialDocumentType
+{
+    Transcript = 1,
+    StudentStatusCertificate = 2
+}
+
+public enum OfficialDocumentStatus
+{
+    Valid = 1,
+    Invalidated = 2,
+    Superseded = 3
+}

src/Jiaowu.Api/Domain/Academic/PeopleAndCourseEntities.cs

@@ -50,6 +50,16 @@ public sealed class Course : CatalogEntity
     public CourseNature Nature { get; set; }
     public AssessmentMethod AssessmentMethod { get; set; }
     public string? Description { get; set; }
+    public ICollection<CoursePrerequisite> Prerequisites { get; set; } = [];
+    public ICollection<CoursePrerequisite> RequiredByCourses { get; set; } = [];
+}
+
+public sealed class CoursePrerequisite : EntityBase
+{
+    public Guid CourseId { get; set; }
+    public Course? Course { get; set; }
+    public Guid PrerequisiteCourseId { get; set; }
+    public Course? PrerequisiteCourse { get; set; }
 }
 
 public sealed class CourseCategory : CatalogEntity

src/Jiaowu.Api/Domain/Academic/ScheduleEntities.cs

@@ -20,6 +20,7 @@ public sealed class ScheduleEntry : EntityBase
     public SchedulePlan? SchedulePlan { get; set; }
     public Guid TeachingTaskId { get; set; }
     public TeachingTask? TeachingTask { get; set; }
+    public ScheduleEntryKind Kind { get; set; } = ScheduleEntryKind.Lecture;
     public Guid? ClassroomId { get; set; }
     public Classroom? Classroom { get; set; }
     public int DayOfWeek { get; set; }
@@ -129,3 +130,9 @@ public enum WeekPattern
     Odd = 2,
     Even = 3
 }
+
+public enum ScheduleEntryKind
+{
+    Lecture = 1,
+    Experiment = 2
+}

src/Jiaowu.Api/Domain/Identity/ApplicationUser.cs

@@ -10,6 +10,8 @@ public sealed class ApplicationUser : IdentityUser<Guid>
     public bool IsEnabled { get; set; } = true;
     public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
     public DateTime? LastLoginAt { get; set; }
+    public string? CalendarSubscriptionStamp { get; set; }
+    public DateTime? CalendarSubscriptionCreatedAt { get; set; }
 }
 
 public sealed class ApplicationRole : IdentityRole<Guid>

src/Jiaowu.Api/Domain/System/AppUpdateRelease.cs

@@ -0,0 +1,40 @@
+using Jiaowu.Api.Domain.Common;
+
+namespace Jiaowu.Api.Domain.System;
+
+public enum AppUpdatePlatform
+{
+    Android,
+    Ios
+}
+
+public enum AppUpdateChannel
+{
+    Production,
+    Staging
+}
+
+public enum AppUpdateReleaseStatus
+{
+    Draft,
+    Published,
+    Archived
+}
+
+public sealed class AppUpdateRelease : EntityBase
+{
+    public AppUpdatePlatform Platform { get; set; }
+    public AppUpdateChannel Channel { get; set; }
+    public required string Version { get; set; }
+    public required string NativeVersion { get; set; }
+    public AppUpdateReleaseStatus Status { get; set; } =
+        AppUpdateReleaseStatus.Draft;
+    public string? ReleaseNotes { get; set; }
+    public required string FileName { get; set; }
+    public long FileSize { get; set; }
+    public required string Sha256 { get; set; }
+    public required byte[] BundleContent { get; set; }
+    public required string CreatedByUserName { get; set; }
+    public string? PublishedByUserName { get; set; }
+    public DateTime? PublishedAt { get; set; }
+}

src/Jiaowu.Api/Domain/System/BackgroundJobOutboxMessage.cs

@@ -0,0 +1,46 @@
+using Jiaowu.Api.Domain.Common;
+
+namespace Jiaowu.Api.Domain.System;
+
+public sealed class BackgroundJobOutboxMessage : EntityBase
+{
+    public BackgroundJobKind JobKind { get; set; }
+    public Guid JobId { get; set; }
+    public BackgroundJobOutboxState State { get; set; } =
+        BackgroundJobOutboxState.Pending;
+    public int PublishAttempts { get; set; }
+    public int ProcessingAttempts { get; set; }
+    public DateTime? PublishedAt { get; set; }
+    public Guid? ProcessingToken { get; set; }
+    public DateTime? LeaseExpiresAt { get; set; }
+    public DateTime? CompletedAt { get; set; }
+    public string? LastError { get; set; }
+
+    public static BackgroundJobOutboxMessage Create(
+        BackgroundJobKind jobKind,
+        Guid jobId) =>
+        new()
+        {
+            JobKind = jobKind,
+            JobId = jobId
+        };
+}
+
+public enum BackgroundJobKind
+{
+    AutomaticSchedule = 1,
+    SchedulePublish = 2,
+    MakeupExamAuto = 3,
+    ExamArrangement = 4,
+    ExamSignInExport = 5,
+    ExamPublish = 6
+}
+
+public enum BackgroundJobOutboxState
+{
+    Pending = 1,
+    Publishing = 2,
+    Published = 3,
+    Processing = 4,
+    Completed = 5
+}

src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobMonitoringService.cs

@@ -0,0 +1,56 @@
+using Jiaowu.Api.Domain.System;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
+
+public sealed record BackgroundJobBacklogSnapshot(
+    int Pending,
+    int Publishing,
+    int Published,
+    int Processing,
+    int ExpiredLeases,
+    DateTime? OldestUnfinishedAt,
+    double? OldestUnfinishedAgeSeconds);
+
+public sealed class BackgroundJobMonitoringService(AppDbContext db)
+{
+    public async Task<BackgroundJobBacklogSnapshot> GetSnapshotAsync(
+        CancellationToken cancellationToken)
+    {
+        var counts = await db.BackgroundJobOutboxMessages.AsNoTracking()
+            .Where(x => x.State != BackgroundJobOutboxState.Completed)
+            .GroupBy(x => x.State)
+            .Select(group => new { State = group.Key, Count = group.Count() })
+            .ToListAsync(cancellationToken);
+        var countByState = counts.ToDictionary(x => x.State, x => x.Count);
+        var now = DateTime.UtcNow;
+        var expiredLeases = await db.BackgroundJobOutboxMessages.AsNoTracking()
+            .CountAsync(
+                x => (x.State == BackgroundJobOutboxState.Publishing ||
+                      x.State == BackgroundJobOutboxState.Processing) &&
+                     x.LeaseExpiresAt != null &&
+                     x.LeaseExpiresAt < now,
+                cancellationToken);
+        var oldestUnfinishedAt = await db.BackgroundJobOutboxMessages
+            .AsNoTracking()
+            .Where(x => x.State != BackgroundJobOutboxState.Completed)
+            .Select(x => (DateTime?)x.CreatedAt)
+            .MinAsync(cancellationToken);
+        double? ageSeconds = oldestUnfinishedAt.HasValue
+            ? Math.Max(0, (now - oldestUnfinishedAt.Value).TotalSeconds)
+            : null;
+
+        return new BackgroundJobBacklogSnapshot(
+            GetCount(BackgroundJobOutboxState.Pending),
+            GetCount(BackgroundJobOutboxState.Publishing),
+            GetCount(BackgroundJobOutboxState.Published),
+            GetCount(BackgroundJobOutboxState.Processing),
+            expiredLeases,
+            oldestUnfinishedAt,
+            ageSeconds);
+
+        int GetCount(BackgroundJobOutboxState state) =>
+            countByState.GetValueOrDefault(state);
+    }
+}

src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobOptions.cs

@@ -0,0 +1,53 @@
+using Jiaowu.Api.Domain.System;
+
+namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
+
+public sealed class BackgroundJobOptions
+{
+    public const string SectionName = "BackgroundJobs";
+
+    public string Transport { get; set; } = "InMemory";
+    public int PollIntervalMilliseconds { get; set; } = 500;
+    public int LeaseSeconds { get; set; } = 120;
+    public ushort PrefetchCount { get; set; } = 1;
+    public int AutomaticScheduleConcurrency { get; set; } = 1;
+    public int SchedulePublishConcurrency { get; set; } = 1;
+    public int MakeupExamAutoConcurrency { get; set; } = 1;
+    public int ExamArrangementConcurrency { get; set; } = 1;
+    public int ExamSignInExportConcurrency { get; set; } = 1;
+    public int ExamPublishConcurrency { get; set; } = 1;
+    public string Exchange { get; set; } = "jiaowu.background-jobs";
+    public string QueuePrefix { get; set; } = "jiaowu.background-jobs";
+    public bool UseQuorumQueues { get; set; } = true;
+    public int ProcessingAttemptLimit { get; set; } = 5;
+    public int MaintenanceIntervalSeconds { get; set; } = 60;
+    public int CompletedRetentionDays { get; set; } = 14;
+    public int CleanupBatchSize { get; set; } = 500;
+
+    public bool UsesRabbitMq =>
+        Transport.Equals("RabbitMq", StringComparison.OrdinalIgnoreCase);
+
+    public int ConsumerConcurrency(BackgroundJobKind kind) => kind switch
+    {
+        BackgroundJobKind.AutomaticSchedule => AutomaticScheduleConcurrency,
+        BackgroundJobKind.SchedulePublish => SchedulePublishConcurrency,
+        BackgroundJobKind.MakeupExamAuto => MakeupExamAutoConcurrency,
+        BackgroundJobKind.ExamArrangement => ExamArrangementConcurrency,
+        BackgroundJobKind.ExamSignInExport => ExamSignInExportConcurrency,
+        BackgroundJobKind.ExamPublish => ExamPublishConcurrency,
+        _ => throw new ArgumentOutOfRangeException(nameof(kind), kind, null)
+    };
+}
+
+public sealed class RabbitMqOptions
+{
+    public const string SectionName = "RabbitMq";
+
+    public string HostName { get; set; } = "localhost";
+    public int Port { get; set; } = 5672;
+    public string UserName { get; set; } = "guest";
+    public string Password { get; set; } = "guest";
+    public string VirtualHost { get; set; } = "/";
+    public bool UseTls { get; set; }
+    public string? TlsServerName { get; set; }
+}

src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobOutboxPublisher.cs

@@ -0,0 +1,329 @@
+using System.Diagnostics;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.System;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
+
+public sealed class BackgroundJobOutboxPublisher(
+    IServiceScopeFactory scopeFactory,
+    IBackgroundJobTransport transport,
+    BackgroundJobOptions options,
+    BackgroundJobTelemetry telemetry,
+    ILogger<BackgroundJobOutboxPublisher> logger) : BackgroundService
+{
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        await PrepareForStartupAsync(stoppingToken);
+        var nextMaintenanceAt = DateTime.MinValue;
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try
+            {
+                if (DateTime.UtcNow >= nextMaintenanceAt)
+                {
+                    await RecoverExpiredProcessingAsync(stoppingToken);
+                    await CleanupCompletedAsync(stoppingToken);
+                    nextMaintenanceAt = DateTime.UtcNow.AddSeconds(
+                        options.MaintenanceIntervalSeconds);
+                }
+
+                var claimed = await ClaimNextAsync(stoppingToken);
+                if (claimed is null)
+                {
+                    await Task.Delay(options.PollIntervalMilliseconds, stoppingToken);
+                    continue;
+                }
+
+                await PublishClaimedAsync(claimed.Value.Message, claimed.Value.Token,
+                    stoppingToken);
+            }
+            catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+            {
+                break;
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(exception, "Background job outbox publishing failed.");
+                await Task.Delay(TimeSpan.FromSeconds(2), stoppingToken);
+            }
+        }
+    }
+
+    private async Task PrepareForStartupAsync(CancellationToken cancellationToken)
+    {
+        await using var scope = scopeFactory.CreateAsyncScope();
+        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+
+        if (!transport.IsDurable)
+        {
+            await db.BackgroundJobOutboxMessages
+                .Where(x => x.State != BackgroundJobOutboxState.Completed)
+                .ExecuteUpdateAsync(
+                    setters => setters
+                        .SetProperty(x => x.State, BackgroundJobOutboxState.Pending)
+                        .SetProperty(x => x.ProcessingToken, (Guid?)null)
+                        .SetProperty(x => x.LeaseExpiresAt, (DateTime?)null),
+                    cancellationToken);
+        }
+
+        await AddMissingOutboxMessagesAsync(db, cancellationToken);
+    }
+
+    private async Task AddMissingOutboxMessagesAsync(
+        AppDbContext db,
+        CancellationToken cancellationToken)
+    {
+        var automaticJobs = await db.AutomaticScheduleJobs.AsNoTracking()
+            .Where(x =>
+                (x.Status == AutomaticScheduleJobStatus.Queued ||
+                 x.Status == AutomaticScheduleJobStatus.Running) &&
+                !db.BackgroundJobOutboxMessages.Any(message =>
+                    message.JobKind == BackgroundJobKind.AutomaticSchedule &&
+                    message.JobId == x.Id))
+            .Select(x => x.Id)
+            .ToListAsync(cancellationToken);
+        var publishJobs = await db.SchedulePublishJobs.AsNoTracking()
+            .Where(x =>
+                (x.Status == SchedulePublishJobStatus.Queued ||
+                 x.Status == SchedulePublishJobStatus.Running) &&
+                !db.BackgroundJobOutboxMessages.Any(message =>
+                    message.JobKind == BackgroundJobKind.SchedulePublish &&
+                    message.JobId == x.Id))
+            .Select(x => x.Id)
+            .ToListAsync(cancellationToken);
+        var makeupJobs = await db.MakeupExamAutoJobs.AsNoTracking()
+            .Where(x =>
+                (x.Status == MakeupExamAutoJobStatus.Queued ||
+                 x.Status == MakeupExamAutoJobStatus.Running) &&
+                !db.BackgroundJobOutboxMessages.Any(message =>
+                    message.JobKind == BackgroundJobKind.MakeupExamAuto &&
+                    message.JobId == x.Id))
+            .Select(x => x.Id)
+            .ToListAsync(cancellationToken);
+        var arrangementJobs = await db.ExamArrangementJobs.AsNoTracking()
+            .Where(x =>
+                (x.Status == ExamArrangementJobStatus.Queued ||
+                 x.Status == ExamArrangementJobStatus.Running) &&
+                !db.BackgroundJobOutboxMessages.Any(message =>
+                    message.JobKind == BackgroundJobKind.ExamArrangement &&
+                    message.JobId == x.Id))
+            .Select(x => x.Id)
+            .ToListAsync(cancellationToken);
+        var exportJobs = await db.ExamSignInExportJobs.AsNoTracking()
+            .Where(x =>
+                (x.Status == ExamSignInExportJobStatus.Queued ||
+                 x.Status == ExamSignInExportJobStatus.Running) &&
+                !db.BackgroundJobOutboxMessages.Any(message =>
+                    message.JobKind == BackgroundJobKind.ExamSignInExport &&
+                    message.JobId == x.Id))
+            .Select(x => x.Id)
+            .ToListAsync(cancellationToken);
+        var publishJobs2 = await db.ExamPublishJobs.AsNoTracking()
+            .Where(x =>
+                (x.Status == ExamPublishJobStatus.Queued ||
+                 x.Status == ExamPublishJobStatus.Running) &&
+                !db.BackgroundJobOutboxMessages.Any(message =>
+                    message.JobKind == BackgroundJobKind.ExamPublish &&
+                    message.JobId == x.Id))
+            .Select(x => x.Id)
+            .ToListAsync(cancellationToken);
+
+        var missingKeys = automaticJobs
+            .Select(id => (BackgroundJobKind.AutomaticSchedule, id))
+            .Concat(publishJobs.Select(id =>
+                (BackgroundJobKind.SchedulePublish, id)))
+            .Concat(makeupJobs.Select(id =>
+                (BackgroundJobKind.MakeupExamAuto, id)))
+            .Concat(arrangementJobs.Select(id =>
+                (BackgroundJobKind.ExamArrangement, id)))
+            .Concat(exportJobs.Select(id =>
+                (BackgroundJobKind.ExamSignInExport, id)))
+            .Concat(publishJobs2.Select(id =>
+                (BackgroundJobKind.ExamPublish, id)))
+            .ToList();
+        foreach (var (kind, jobId) in missingKeys)
+        {
+            db.BackgroundJobOutboxMessages.Add(
+                BackgroundJobOutboxMessage.Create(kind, jobId));
+        }
+
+        if (!db.ChangeTracker.HasChanges())
+            return;
+
+        try
+        {
+            await db.SaveChangesAsync(cancellationToken);
+        }
+        catch (DbUpdateException)
+        {
+            db.ChangeTracker.Clear();
+            foreach (var (kind, jobId) in missingKeys)
+            {
+                var recovered = await db.BackgroundJobOutboxMessages
+                    .AsNoTracking()
+                    .AnyAsync(
+                        message => message.JobKind == kind &&
+                                   message.JobId == jobId,
+                        cancellationToken);
+                if (!recovered)
+                    throw;
+            }
+
+            logger.LogInformation(
+                "Another application instance recovered {Count} missing outbox messages first.",
+                missingKeys.Count);
+        }
+    }
+
+    private async Task CleanupCompletedAsync(CancellationToken cancellationToken)
+    {
+        await using var scope = scopeFactory.CreateAsyncScope();
+        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+        var cutoff = DateTime.UtcNow.AddDays(-options.CompletedRetentionDays);
+        var completedIds = await db.BackgroundJobOutboxMessages.AsNoTracking()
+            .Where(x =>
+                x.State == BackgroundJobOutboxState.Completed &&
+                x.CompletedAt != null &&
+                x.CompletedAt < cutoff)
+            .OrderBy(x => x.CompletedAt)
+            .Select(x => x.Id)
+            .Take(options.CleanupBatchSize)
+            .ToListAsync(cancellationToken);
+        if (completedIds.Count == 0)
+            return;
+
+        foreach (var id in completedIds)
+        {
+            db.BackgroundJobOutboxMessages.Remove(
+                new BackgroundJobOutboxMessage { Id = id });
+        }
+        await db.SaveChangesAsync(cancellationToken);
+        telemetry.RecordCleaned(completedIds.Count);
+        logger.LogInformation(
+            "Removed {Count} completed background job outbox messages older than {Cutoff}.",
+            completedIds.Count,
+            cutoff);
+    }
+
+    private async Task RecoverExpiredProcessingAsync(
+        CancellationToken cancellationToken)
+    {
+        await using var scope = scopeFactory.CreateAsyncScope();
+        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+        var now = DateTime.UtcNow;
+        var recoveredState = transport.IsDurable
+            ? BackgroundJobOutboxState.Published
+            : BackgroundJobOutboxState.Pending;
+
+        await db.BackgroundJobOutboxMessages
+            .Where(x =>
+                (x.State == BackgroundJobOutboxState.Publishing ||
+                 x.State == BackgroundJobOutboxState.Processing) &&
+                x.LeaseExpiresAt != null &&
+                x.LeaseExpiresAt < now)
+            .ExecuteUpdateAsync(
+                setters => setters
+                    .SetProperty(x => x.State, recoveredState)
+                    .SetProperty(x => x.ProcessingToken, (Guid?)null)
+                    .SetProperty(x => x.LeaseExpiresAt, (DateTime?)null),
+                cancellationToken);
+    }
+
+    private async Task<(BackgroundJobEnvelope Message, Guid Token)?> ClaimNextAsync(
+        CancellationToken cancellationToken)
+    {
+        await using var scope = scopeFactory.CreateAsyncScope();
+        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+        var candidateId = await db.BackgroundJobOutboxMessages.AsNoTracking()
+            .Where(x => x.State == BackgroundJobOutboxState.Pending)
+            .OrderBy(x => x.CreatedAt)
+            .Select(x => (Guid?)x.Id)
+            .FirstOrDefaultAsync(cancellationToken);
+        if (!candidateId.HasValue)
+            return null;
+
+        var token = Guid.NewGuid();
+        var leaseExpiresAt = DateTime.UtcNow.AddSeconds(options.LeaseSeconds);
+        var claimed = await db.BackgroundJobOutboxMessages
+            .Where(x =>
+                x.Id == candidateId.Value &&
+                x.State == BackgroundJobOutboxState.Pending)
+            .ExecuteUpdateAsync(
+                setters => setters
+                    .SetProperty(x => x.State, BackgroundJobOutboxState.Publishing)
+                    .SetProperty(x => x.ProcessingToken, token)
+                    .SetProperty(x => x.LeaseExpiresAt, leaseExpiresAt)
+                    .SetProperty(x => x.PublishAttempts, x => x.PublishAttempts + 1)
+                    .SetProperty(x => x.LastError, (string?)null),
+                cancellationToken);
+        if (claimed == 0)
+            return null;
+
+        var message = await db.BackgroundJobOutboxMessages.AsNoTracking()
+            .Where(x => x.Id == candidateId.Value)
+            .Select(x => new BackgroundJobEnvelope(x.Id, x.JobKind, x.JobId))
+            .SingleAsync(cancellationToken);
+        return (message, token);
+    }
+
+    private async Task PublishClaimedAsync(
+        BackgroundJobEnvelope message,
+        Guid token,
+        CancellationToken cancellationToken)
+    {
+        var startedAt = Stopwatch.GetTimestamp();
+        try
+        {
+            await transport.PublishAsync(message, cancellationToken);
+
+            await using var scope = scopeFactory.CreateAsyncScope();
+            var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+            await db.BackgroundJobOutboxMessages
+                .Where(x =>
+                    x.Id == message.OutboxMessageId &&
+                    x.State == BackgroundJobOutboxState.Publishing &&
+                    x.ProcessingToken == token)
+                .ExecuteUpdateAsync(
+                    setters => setters
+                        .SetProperty(x => x.State, BackgroundJobOutboxState.Published)
+                        .SetProperty(x => x.PublishedAt, DateTime.UtcNow)
+                        .SetProperty(x => x.ProcessingToken, (Guid?)null)
+                        .SetProperty(x => x.LeaseExpiresAt, (DateTime?)null),
+                    cancellationToken);
+            telemetry.RecordPublish(
+                message.JobKind,
+                transport.IsDurable,
+                "published",
+                Stopwatch.GetElapsedTime(startedAt));
+        }
+        catch (Exception exception)
+        {
+            await using var scope = scopeFactory.CreateAsyncScope();
+            var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+            var messageText = exception.GetBaseException().Message;
+            if (messageText.Length > 2000)
+                messageText = messageText[..2000];
+            await db.BackgroundJobOutboxMessages
+                .Where(x =>
+                    x.Id == message.OutboxMessageId &&
+                    x.State == BackgroundJobOutboxState.Publishing &&
+                    x.ProcessingToken == token)
+                .ExecuteUpdateAsync(
+                    setters => setters
+                        .SetProperty(x => x.State, BackgroundJobOutboxState.Pending)
+                        .SetProperty(x => x.ProcessingToken, (Guid?)null)
+                        .SetProperty(x => x.LeaseExpiresAt, (DateTime?)null)
+                        .SetProperty(x => x.LastError, messageText),
+                    cancellationToken);
+            telemetry.RecordPublish(
+                message.JobKind,
+                transport.IsDurable,
+                "failed",
+                Stopwatch.GetElapsedTime(startedAt));
+            throw;
+        }
+    }
+}

src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobRunner.cs

@@ -0,0 +1,397 @@
+using System.Diagnostics;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.System;
+using Jiaowu.Api.Infrastructure.Exams;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Scheduling;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
+
+public sealed record BackgroundJobRunResult(
+    BackgroundJobRunOutcome Outcome,
+    TimeSpan RetryAfter)
+{
+    public static BackgroundJobRunResult Completed { get; } =
+        new(BackgroundJobRunOutcome.Completed, TimeSpan.Zero);
+
+    public static BackgroundJobRunResult Retry(TimeSpan retryAfter) =>
+        new(BackgroundJobRunOutcome.Retry, retryAfter);
+}
+
+public enum BackgroundJobRunOutcome
+{
+    Completed,
+    Retry
+}
+
+public sealed class BackgroundJobRunner(
+    IServiceScopeFactory scopeFactory,
+    IBackgroundJobTransport transport,
+    BackgroundJobOptions options,
+    BackgroundJobTelemetry telemetry,
+    ILogger<BackgroundJobRunner> logger)
+{
+    public async Task<BackgroundJobRunResult> RunAsync(
+        BackgroundJobEnvelope message,
+        CancellationToken cancellationToken)
+    {
+        var startedAt = Stopwatch.GetTimestamp();
+        var token = Guid.NewGuid();
+        var claim = await TryClaimAsync(message, token, cancellationToken);
+        if (!claim.Claimed)
+        {
+            return claim.Completed
+                ? BackgroundJobRunResult.Completed
+                : BackgroundJobRunResult.Retry(claim.RetryAfter);
+        }
+
+        if (claim.AttemptsExceeded)
+        {
+            await MarkJobRetryLimitExceededAsync(message, cancellationToken);
+            await MarkCompletedAsync(message.OutboxMessageId, token,
+                cancellationToken);
+            telemetry.RecordProcessing(
+                message.JobKind,
+                "retry-limit",
+                Stopwatch.GetElapsedTime(startedAt));
+            return BackgroundJobRunResult.Completed;
+        }
+
+        using var heartbeatCancellation =
+            CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+        var heartbeat = RunHeartbeatAsync(
+            message.OutboxMessageId,
+            token,
+            heartbeatCancellation.Token);
+
+        try
+        {
+            await using var scope = scopeFactory.CreateAsyncScope();
+            switch (message.JobKind)
+            {
+                case BackgroundJobKind.AutomaticSchedule:
+                    await scope.ServiceProvider
+                        .GetRequiredService<AutomaticScheduleJobProcessor>()
+                        .ProcessAsync(message.JobId, cancellationToken);
+                    break;
+                case BackgroundJobKind.SchedulePublish:
+                    await scope.ServiceProvider
+                        .GetRequiredService<SchedulePublishJobProcessor>()
+                        .ProcessAsync(message.JobId, cancellationToken);
+                    break;
+                case BackgroundJobKind.MakeupExamAuto:
+                    await scope.ServiceProvider
+                        .GetRequiredService<MakeupExamAutoJobProcessor>()
+                        .ProcessAsync(message.JobId, cancellationToken);
+                    break;
+                case BackgroundJobKind.ExamArrangement:
+                    await scope.ServiceProvider
+                        .GetRequiredService<ExamArrangementJobProcessor>()
+                        .ProcessAsync(message.JobId, cancellationToken);
+                    break;
+                case BackgroundJobKind.ExamSignInExport:
+                    await scope.ServiceProvider
+                        .GetRequiredService<ExamSignInExportJobProcessor>()
+                        .ProcessAsync(message.JobId, cancellationToken);
+                    break;
+                case BackgroundJobKind.ExamPublish:
+                    await scope.ServiceProvider
+                        .GetRequiredService<ExamPublishJobProcessor>()
+                        .ProcessAsync(message.JobId, cancellationToken);
+                    break;
+                default:
+                    throw new InvalidOperationException(
+                        $"Unsupported background job kind '{message.JobKind}'.");
+            }
+
+            await MarkCompletedAsync(message.OutboxMessageId, token,
+                cancellationToken);
+            telemetry.RecordProcessing(
+                message.JobKind,
+                "completed",
+                Stopwatch.GetElapsedTime(startedAt));
+            return BackgroundJobRunResult.Completed;
+        }
+        catch (OperationCanceledException) when (cancellationToken.IsCancellationRequested)
+        {
+            throw;
+        }
+        catch (Exception exception)
+        {
+            logger.LogError(
+                exception,
+                "Background job {JobKind}/{JobId} will be retried.",
+                message.JobKind,
+                message.JobId);
+            await ReleaseForRetryAsync(
+                message.OutboxMessageId,
+                token,
+                exception,
+                CancellationToken.None);
+            telemetry.RecordProcessing(
+                message.JobKind,
+                "retry",
+                Stopwatch.GetElapsedTime(startedAt));
+            return BackgroundJobRunResult.Retry(TimeSpan.FromSeconds(2));
+        }
+        finally
+        {
+            await heartbeatCancellation.CancelAsync();
+            try
+            {
+                await heartbeat;
+            }
+            catch (OperationCanceledException)
+            {
+                // Expected when processing completes or the application stops.
+            }
+        }
+    }
+
+    private async Task<(
+        bool Claimed,
+        bool Completed,
+        bool AttemptsExceeded,
+        TimeSpan RetryAfter)>
+        TryClaimAsync(
+            BackgroundJobEnvelope message,
+            Guid token,
+            CancellationToken cancellationToken)
+    {
+        await using var scope = scopeFactory.CreateAsyncScope();
+        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+        var now = DateTime.UtcNow;
+        var leaseExpiresAt = now.AddSeconds(options.LeaseSeconds);
+        var claimed = await db.BackgroundJobOutboxMessages
+            .Where(x =>
+                x.Id == message.OutboxMessageId &&
+                x.JobKind == message.JobKind &&
+                x.JobId == message.JobId &&
+                (x.State == BackgroundJobOutboxState.Pending ||
+                 x.State == BackgroundJobOutboxState.Publishing ||
+                 x.State == BackgroundJobOutboxState.Published ||
+                 (x.State == BackgroundJobOutboxState.Processing &&
+                  x.LeaseExpiresAt != null &&
+                  x.LeaseExpiresAt < now)))
+            .ExecuteUpdateAsync(
+                setters => setters
+                    .SetProperty(x => x.State, BackgroundJobOutboxState.Processing)
+                    .SetProperty(x => x.ProcessingToken, token)
+                    .SetProperty(x => x.LeaseExpiresAt, leaseExpiresAt)
+                    .SetProperty(
+                        x => x.ProcessingAttempts,
+                        x => x.ProcessingAttempts + 1)
+                    .SetProperty(x => x.LastError, (string?)null),
+                cancellationToken);
+        if (claimed == 1)
+        {
+            var attempts = await db.BackgroundJobOutboxMessages.AsNoTracking()
+                .Where(x => x.Id == message.OutboxMessageId)
+                .Select(x => x.ProcessingAttempts)
+                .SingleAsync(cancellationToken);
+            return (
+                true,
+                false,
+                attempts > options.ProcessingAttemptLimit,
+                TimeSpan.Zero);
+        }
+
+        var current = await db.BackgroundJobOutboxMessages.AsNoTracking()
+            .Where(x => x.Id == message.OutboxMessageId)
+            .Select(x => new { x.State, x.LeaseExpiresAt })
+            .FirstOrDefaultAsync(cancellationToken);
+        if (current is null || current.State == BackgroundJobOutboxState.Completed)
+            return (false, true, false, TimeSpan.Zero);
+
+        var retryAfter = current.LeaseExpiresAt.HasValue
+            ? current.LeaseExpiresAt.Value - now
+            : TimeSpan.FromSeconds(2);
+        retryAfter = TimeSpan.FromSeconds(Math.Clamp(
+            retryAfter.TotalSeconds,
+            1,
+            options.LeaseSeconds));
+        return (false, false, false, retryAfter);
+    }
+
+    private async Task MarkJobRetryLimitExceededAsync(
+        BackgroundJobEnvelope message,
+        CancellationToken cancellationToken)
+    {
+        await using var scope = scopeFactory.CreateAsyncScope();
+        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+        var completedAt = DateTime.UtcNow;
+        var error = $"后台任务连续处理失败超过 {options.ProcessingAttemptLimit} 次，" +
+                    "已停止自动重试，请检查服务日志后重新创建任务。";
+
+        switch (message.JobKind)
+        {
+            case BackgroundJobKind.AutomaticSchedule:
+                await db.AutomaticScheduleJobs
+                    .Where(x =>
+                        x.Id == message.JobId &&
+                        x.Status != AutomaticScheduleJobStatus.Succeeded &&
+                        x.Status != AutomaticScheduleJobStatus.Failed)
+                    .ExecuteUpdateAsync(
+                        setters => setters
+                            .SetProperty(
+                                x => x.Status,
+                                AutomaticScheduleJobStatus.Failed)
+                            .SetProperty(x => x.ActiveSchedulePlanId, (Guid?)null)
+                            .SetProperty(x => x.ErrorMessage, error)
+                            .SetProperty(x => x.CompletedAt, completedAt),
+                        cancellationToken);
+                break;
+            case BackgroundJobKind.SchedulePublish:
+                await db.SchedulePublishJobs
+                    .Where(x =>
+                        x.Id == message.JobId &&
+                        x.Status != SchedulePublishJobStatus.Succeeded &&
+                        x.Status != SchedulePublishJobStatus.Failed)
+                    .ExecuteUpdateAsync(
+                        setters => setters
+                            .SetProperty(
+                                x => x.Status,
+                                SchedulePublishJobStatus.Failed)
+                            .SetProperty(x => x.ActiveAcademicTermId, (Guid?)null)
+                            .SetProperty(x => x.CurrentStep, "后台处理已停止")
+                            .SetProperty(x => x.ErrorMessage, error)
+                            .SetProperty(x => x.CompletedAt, completedAt),
+                        cancellationToken);
+                break;
+            case BackgroundJobKind.MakeupExamAuto:
+                await db.MakeupExamAutoJobs
+                    .Where(x =>
+                        x.Id == message.JobId &&
+                        x.Status != MakeupExamAutoJobStatus.Succeeded &&
+                        x.Status != MakeupExamAutoJobStatus.Failed)
+                    .ExecuteUpdateAsync(
+                        setters => setters
+                            .SetProperty(
+                                x => x.Status,
+                                MakeupExamAutoJobStatus.Failed)
+                            .SetProperty(x => x.ErrorMessage, error)
+                            .SetProperty(x => x.CompletedAt, completedAt),
+                        cancellationToken);
+                break;
+            case BackgroundJobKind.ExamArrangement:
+                await db.ExamArrangementJobs
+                    .Where(x =>
+                        x.Id == message.JobId &&
+                        x.Status != ExamArrangementJobStatus.Succeeded &&
+                        x.Status != ExamArrangementJobStatus.Failed)
+                    .ExecuteUpdateAsync(
+                        setters => setters
+                            .SetProperty(
+                                x => x.Status,
+                                ExamArrangementJobStatus.Failed)
+                            .SetProperty(x => x.ActivePlanId, (Guid?)null)
+                            .SetProperty(x => x.CurrentStep, "后台处理已停止")
+                            .SetProperty(x => x.ErrorMessage, error)
+                            .SetProperty(x => x.CompletedAt, completedAt),
+                        cancellationToken);
+                break;
+            case BackgroundJobKind.ExamPublish:
+                await db.ExamPublishJobs
+                    .Where(x =>
+                        x.Id == message.JobId &&
+                        x.Status != ExamPublishJobStatus.Succeeded &&
+                        x.Status != ExamPublishJobStatus.Failed)
+                    .ExecuteUpdateAsync(
+                        setters => setters
+                            .SetProperty(
+                                x => x.Status,
+                                ExamPublishJobStatus.Failed)
+                            .SetProperty(x => x.ActivePlanId, (Guid?)null)
+                            .SetProperty(x => x.CurrentStep, "后台处理已停止")
+                            .SetProperty(x => x.ErrorMessage, error)
+                            .SetProperty(x => x.CompletedAt, completedAt),
+                        cancellationToken);
+                break;
+            default:
+                throw new ArgumentOutOfRangeException(
+                    nameof(message.JobKind),
+                    message.JobKind,
+                    null);
+        }
+
+        logger.LogError(
+            "Background job {JobKind}/{JobId} exceeded {AttemptLimit} processing attempts.",
+            message.JobKind,
+            message.JobId,
+            options.ProcessingAttemptLimit);
+    }
+
+    private async Task RunHeartbeatAsync(
+        Guid outboxMessageId,
+        Guid token,
+        CancellationToken cancellationToken)
+    {
+        var intervalSeconds = Math.Max(5, options.LeaseSeconds / 3);
+        while (!cancellationToken.IsCancellationRequested)
+        {
+            await Task.Delay(TimeSpan.FromSeconds(intervalSeconds), cancellationToken);
+            await using var scope = scopeFactory.CreateAsyncScope();
+            var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+            await db.BackgroundJobOutboxMessages
+                .Where(x =>
+                    x.Id == outboxMessageId &&
+                    x.State == BackgroundJobOutboxState.Processing &&
+                    x.ProcessingToken == token)
+                .ExecuteUpdateAsync(
+                    setters => setters.SetProperty(
+                        x => x.LeaseExpiresAt,
+                        DateTime.UtcNow.AddSeconds(options.LeaseSeconds)),
+                    cancellationToken);
+        }
+    }
+
+    private async Task MarkCompletedAsync(
+        Guid outboxMessageId,
+        Guid token,
+        CancellationToken cancellationToken)
+    {
+        await using var scope = scopeFactory.CreateAsyncScope();
+        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+        await db.BackgroundJobOutboxMessages
+            .Where(x =>
+                x.Id == outboxMessageId &&
+                x.State == BackgroundJobOutboxState.Processing &&
+                x.ProcessingToken == token)
+            .ExecuteUpdateAsync(
+                setters => setters
+                    .SetProperty(x => x.State, BackgroundJobOutboxState.Completed)
+                    .SetProperty(x => x.CompletedAt, DateTime.UtcNow)
+                    .SetProperty(x => x.ProcessingToken, (Guid?)null)
+                    .SetProperty(x => x.LeaseExpiresAt, (DateTime?)null),
+                cancellationToken);
+    }
+
+    private async Task ReleaseForRetryAsync(
+        Guid outboxMessageId,
+        Guid token,
+        Exception exception,
+        CancellationToken cancellationToken)
+    {
+        await using var scope = scopeFactory.CreateAsyncScope();
+        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+        var message = exception.GetBaseException().Message;
+        if (message.Length > 2000)
+            message = message[..2000];
+        var state = transport.IsDurable
+            ? BackgroundJobOutboxState.Published
+            : BackgroundJobOutboxState.Pending;
+        await db.BackgroundJobOutboxMessages
+            .Where(x =>
+                x.Id == outboxMessageId &&
+                x.State == BackgroundJobOutboxState.Processing &&
+                x.ProcessingToken == token)
+            .ExecuteUpdateAsync(
+                setters => setters
+                    .SetProperty(x => x.State, state)
+                    .SetProperty(x => x.ProcessingToken, (Guid?)null)
+                    .SetProperty(x => x.LeaseExpiresAt, (DateTime?)null)
+                    .SetProperty(x => x.LastError, message),
+                cancellationToken);
+    }
+}

src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobTelemetry.cs

@@ -0,0 +1,74 @@
+using System.Diagnostics;
+using System.Diagnostics.Metrics;
+using Jiaowu.Api.Domain.System;
+
+namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
+
+public sealed class BackgroundJobTelemetry : IDisposable
+{
+    public const string MeterName = "Jiaowu.BackgroundJobs";
+
+    private readonly Meter _meter = new(MeterName, "1.0.0");
+    private readonly Counter<long> _published;
+    private readonly Counter<long> _processed;
+    private readonly Histogram<double> _publishDuration;
+    private readonly Histogram<double> _processingDuration;
+    private readonly Counter<long> _cleaned;
+
+    public BackgroundJobTelemetry()
+    {
+        _published = _meter.CreateCounter<long>(
+            "jiaowu.background_jobs.published",
+            unit: "{message}");
+        _processed = _meter.CreateCounter<long>(
+            "jiaowu.background_jobs.processed",
+            unit: "{job}");
+        _publishDuration = _meter.CreateHistogram<double>(
+            "jiaowu.background_jobs.publish.duration",
+            unit: "ms");
+        _processingDuration = _meter.CreateHistogram<double>(
+            "jiaowu.background_jobs.processing.duration",
+            unit: "ms");
+        _cleaned = _meter.CreateCounter<long>(
+            "jiaowu.background_jobs.outbox.cleaned",
+            unit: "{message}");
+    }
+
+    public void RecordPublish(
+        BackgroundJobKind kind,
+        bool durable,
+        string outcome,
+        TimeSpan duration)
+    {
+        var tags = new TagList
+        {
+            { "job.kind", kind.ToString() },
+            { "messaging.backend", durable ? "rabbitmq" : "memory" },
+            { "job.outcome", outcome }
+        };
+        _published.Add(1, tags);
+        _publishDuration.Record(duration.TotalMilliseconds, tags);
+    }
+
+    public void RecordProcessing(
+        BackgroundJobKind kind,
+        string outcome,
+        TimeSpan duration)
+    {
+        var tags = new TagList
+        {
+            { "job.kind", kind.ToString() },
+            { "job.outcome", outcome }
+        };
+        _processed.Add(1, tags);
+        _processingDuration.Record(duration.TotalMilliseconds, tags);
+    }
+
+    public void RecordCleaned(int count)
+    {
+        if (count > 0)
+            _cleaned.Add(count);
+    }
+
+    public void Dispose() => _meter.Dispose();
+}

src/Jiaowu.Api/Infrastructure/BackgroundJobs/BackgroundJobTransport.cs

@@ -0,0 +1,51 @@
+using System.Threading.Channels;
+using Jiaowu.Api.Domain.System;
+
+namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
+
+public sealed record BackgroundJobEnvelope(
+    Guid OutboxMessageId,
+    BackgroundJobKind JobKind,
+    Guid JobId);
+
+public interface IBackgroundJobTransport
+{
+    bool IsDurable { get; }
+
+    ValueTask PublishAsync(
+        BackgroundJobEnvelope message,
+        CancellationToken cancellationToken);
+
+    Task<bool> CheckHealthAsync(CancellationToken cancellationToken);
+}
+
+public sealed class InMemoryBackgroundJobTransport : IBackgroundJobTransport
+{
+    private readonly IReadOnlyDictionary<
+        BackgroundJobKind,
+        Channel<BackgroundJobEnvelope>> _channels =
+        Enum.GetValues<BackgroundJobKind>().ToDictionary(
+            kind => kind,
+            _ => Channel.CreateBounded<BackgroundJobEnvelope>(
+                new BoundedChannelOptions(256)
+                {
+                    FullMode = BoundedChannelFullMode.Wait,
+                    SingleReader = false,
+                    SingleWriter = false
+                }));
+
+    public bool IsDurable => false;
+
+    public ValueTask PublishAsync(
+        BackgroundJobEnvelope message,
+        CancellationToken cancellationToken) =>
+        _channels[message.JobKind].Writer.WriteAsync(message, cancellationToken);
+
+    public Task<bool> CheckHealthAsync(CancellationToken cancellationToken) =>
+        Task.FromResult(true);
+
+    public IAsyncEnumerable<BackgroundJobEnvelope> ReadAllAsync(
+        BackgroundJobKind kind,
+        CancellationToken cancellationToken) =>
+        _channels[kind].Reader.ReadAllAsync(cancellationToken);
+}

src/Jiaowu.Api/Infrastructure/BackgroundJobs/InMemoryBackgroundJobWorker.cs

@@ -0,0 +1,46 @@
+using Jiaowu.Api.Domain.System;
+
+namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
+
+public sealed class InMemoryBackgroundJobWorker(
+    InMemoryBackgroundJobTransport transport,
+    BackgroundJobRunner runner,
+    BackgroundJobOptions options,
+    ILogger<InMemoryBackgroundJobWorker> logger) : BackgroundService
+{
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        var workers = Enum.GetValues<BackgroundJobKind>()
+            .SelectMany(kind => Enumerable.Range(
+                    0,
+                    options.ConsumerConcurrency(kind))
+                .Select(_ => ConsumeAsync(kind, stoppingToken)))
+            .ToArray();
+
+        try
+        {
+            await Task.WhenAll(workers);
+        }
+        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+        {
+            logger.LogInformation("In-memory background job worker is stopping.");
+        }
+    }
+
+    private async Task ConsumeAsync(
+        BackgroundJobKind kind,
+        CancellationToken cancellationToken)
+    {
+        await foreach (var message in transport.ReadAllAsync(
+                           kind,
+                           cancellationToken))
+        {
+            var result = await runner.RunAsync(message, cancellationToken);
+            if (result.Outcome != BackgroundJobRunOutcome.Retry)
+                continue;
+
+            await Task.Delay(result.RetryAfter, cancellationToken);
+            await transport.PublishAsync(message, cancellationToken);
+        }
+    }
+}

src/Jiaowu.Api/Infrastructure/BackgroundJobs/RabbitMqBackgroundJobs.cs

@@ -0,0 +1,437 @@
+using System.Text.Json;
+using Jiaowu.Api.Domain.System;
+using RabbitMQ.Client;
+using RabbitMQ.Client.Events;
+
+namespace Jiaowu.Api.Infrastructure.BackgroundJobs;
+
+public sealed class RabbitMqBackgroundJobTransport(
+    BackgroundJobOptions jobOptions,
+    RabbitMqOptions rabbitOptions,
+    ILogger<RabbitMqBackgroundJobTransport> logger)
+    : IBackgroundJobTransport, IAsyncDisposable
+{
+    private readonly SemaphoreSlim _gate = new(1, 1);
+    private IConnection? _connection;
+    private IChannel? _channel;
+
+    public bool IsDurable => true;
+
+    public async ValueTask PublishAsync(
+        BackgroundJobEnvelope message,
+        CancellationToken cancellationToken)
+    {
+        var body = JsonSerializer.SerializeToUtf8Bytes(message);
+        await _gate.WaitAsync(cancellationToken);
+        try
+        {
+            var channel = await GetChannelAsync(cancellationToken);
+            var properties = new BasicProperties
+            {
+                Persistent = true,
+                ContentType = "application/json",
+                MessageId = message.OutboxMessageId.ToString("D"),
+                Type = message.JobKind.ToString(),
+                AppId = "jiaowu-api"
+            };
+            await channel.BasicPublishAsync(
+                jobOptions.Exchange,
+                RabbitMqBackgroundJobTopology.RoutingKey(message.JobKind),
+                mandatory: true,
+                properties,
+                body,
+                cancellationToken);
+        }
+        catch
+        {
+            await ResetConnectionAsync();
+            throw;
+        }
+        finally
+        {
+            _gate.Release();
+        }
+    }
+
+    public async Task<bool> CheckHealthAsync(CancellationToken cancellationToken)
+    {
+        await _gate.WaitAsync(cancellationToken);
+        try
+        {
+            var channel = await GetChannelAsync(cancellationToken);
+            return channel.IsOpen;
+        }
+        catch (Exception exception)
+        {
+            logger.LogWarning(exception, "RabbitMQ health check failed.");
+            await ResetConnectionAsync();
+            return false;
+        }
+        finally
+        {
+            _gate.Release();
+        }
+    }
+
+    private async Task<IChannel> GetChannelAsync(CancellationToken cancellationToken)
+    {
+        if (_channel is { IsOpen: true })
+            return _channel;
+
+        await ResetConnectionAsync();
+        _connection = await RabbitMqBackgroundJobTopology.CreateConnectionAsync(
+            rabbitOptions,
+            "jiaowu-background-job-publisher",
+            consumerDispatchConcurrency: 1,
+            cancellationToken);
+        _channel = await _connection.CreateChannelAsync(
+            new CreateChannelOptions(
+                publisherConfirmationsEnabled: true,
+                publisherConfirmationTrackingEnabled: true),
+            cancellationToken);
+        await RabbitMqBackgroundJobTopology.DeclareAsync(
+            _channel,
+            jobOptions,
+            cancellationToken);
+        return _channel;
+    }
+
+    private async Task ResetConnectionAsync()
+    {
+        if (_channel is not null)
+        {
+            try
+            {
+                await _channel.DisposeAsync();
+            }
+            catch
+            {
+                // The broker may already have closed the channel.
+            }
+            _channel = null;
+        }
+
+        if (_connection is not null)
+        {
+            try
+            {
+                await _connection.DisposeAsync();
+            }
+            catch
+            {
+                // The broker may already have closed the connection.
+            }
+            _connection = null;
+        }
+    }
+
+    public async ValueTask DisposeAsync()
+    {
+        await _gate.WaitAsync();
+        try
+        {
+            await ResetConnectionAsync();
+        }
+        finally
+        {
+            _gate.Release();
+            _gate.Dispose();
+        }
+    }
+}
+
+public sealed class RabbitMqBackgroundJobWorker(
+    BackgroundJobOptions jobOptions,
+    RabbitMqOptions rabbitOptions,
+    BackgroundJobRunner runner,
+    ILogger<RabbitMqBackgroundJobWorker> logger) : BackgroundService
+{
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            IConnection? connection = null;
+            var channels = new List<IChannel>();
+            try
+            {
+                var consumerCount = RabbitMqBackgroundJobTopology.JobKinds.Sum(
+                    jobOptions.ConsumerConcurrency);
+                connection = await RabbitMqBackgroundJobTopology.CreateConnectionAsync(
+                    rabbitOptions,
+                    "jiaowu-background-job-worker",
+                    (ushort)consumerCount,
+                    stoppingToken);
+
+                foreach (var kind in RabbitMqBackgroundJobTopology.JobKinds)
+                {
+                    for (var workerIndex = 0;
+                         workerIndex < jobOptions.ConsumerConcurrency(kind);
+                         workerIndex++)
+                    {
+                        var channel = await connection.CreateChannelAsync(
+                            new CreateChannelOptions(
+                                publisherConfirmationsEnabled: false,
+                                publisherConfirmationTrackingEnabled: false),
+                            stoppingToken);
+                        channels.Add(channel);
+                        await RabbitMqBackgroundJobTopology.DeclareAsync(
+                            channel,
+                            jobOptions,
+                            stoppingToken);
+                        await channel.BasicQosAsync(
+                            0,
+                            jobOptions.PrefetchCount,
+                            global: false,
+                            stoppingToken);
+
+                        var consumer = new AsyncEventingBasicConsumer(channel);
+                        consumer.ReceivedAsync += async (_, eventArgs) =>
+                        {
+                            using var deliveryCancellation =
+                                CancellationTokenSource.CreateLinkedTokenSource(
+                                    eventArgs.CancellationToken,
+                                    stoppingToken);
+                            var deliveryToken = deliveryCancellation.Token;
+                            try
+                            {
+                                var message = JsonSerializer
+                                    .Deserialize<BackgroundJobEnvelope>(
+                                        eventArgs.Body.Span);
+                                if (message is null || message.JobKind != kind)
+                                {
+                                    await channel.BasicNackAsync(
+                                        eventArgs.DeliveryTag,
+                                        multiple: false,
+                                        requeue: false,
+                                        deliveryToken);
+                                    return;
+                                }
+
+                                var result = await runner.RunAsync(
+                                    message,
+                                    deliveryToken);
+                                if (result.Outcome ==
+                                    BackgroundJobRunOutcome.Completed)
+                                {
+                                    await channel.BasicAckAsync(
+                                        eventArgs.DeliveryTag,
+                                        multiple: false,
+                                        deliveryToken);
+                                    return;
+                                }
+
+                                await Task.Delay(
+                                    result.RetryAfter,
+                                    deliveryToken);
+                                await channel.BasicNackAsync(
+                                    eventArgs.DeliveryTag,
+                                    multiple: false,
+                                    requeue: true,
+                                    deliveryToken);
+                            }
+                            catch (OperationCanceledException)
+                            {
+                                // Closing the channel requeues unacknowledged deliveries.
+                            }
+                            catch (Exception exception)
+                            {
+                                logger.LogError(
+                                    exception,
+                                    "RabbitMQ delivery for {JobKind} failed and will be requeued.",
+                                    kind);
+                                if (!channel.IsOpen)
+                                    return;
+
+                                await channel.BasicNackAsync(
+                                    eventArgs.DeliveryTag,
+                                    multiple: false,
+                                    requeue: true,
+                                    CancellationToken.None);
+                            }
+                        };
+                        await channel.BasicConsumeAsync(
+                            RabbitMqBackgroundJobTopology.QueueName(
+                                jobOptions,
+                                kind),
+                            autoAck: false,
+                            consumer,
+                            stoppingToken);
+                    }
+                }
+
+                logger.LogInformation(
+                    "{ConsumerCount} RabbitMQ background job consumers are connected to {HostName}:{Port}.",
+                    consumerCount,
+                    rabbitOptions.HostName,
+                    rabbitOptions.Port);
+                while (connection.IsOpen && !stoppingToken.IsCancellationRequested)
+                    await Task.Delay(TimeSpan.FromSeconds(1), stoppingToken);
+            }
+            catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+            {
+                break;
+            }
+            catch (Exception exception)
+            {
+                logger.LogError(
+                    exception,
+                    "RabbitMQ background job consumer connection failed; retrying.");
+            }
+            finally
+            {
+                foreach (var channel in channels)
+                {
+                    try
+                    {
+                        await channel.DisposeAsync();
+                    }
+                    catch
+                    {
+                        // The connection may already have disposed its channels.
+                    }
+                }
+
+                if (connection is not null)
+                {
+                    try
+                    {
+                        await connection.DisposeAsync();
+                    }
+                    catch
+                    {
+                        // The broker may already have closed the connection.
+                    }
+                }
+            }
+
+            if (!stoppingToken.IsCancellationRequested)
+                await Task.Delay(TimeSpan.FromSeconds(5), stoppingToken);
+        }
+    }
+}
+
+internal static class RabbitMqBackgroundJobTopology
+{
+    public static readonly BackgroundJobKind[] JobKinds =
+    [
+        BackgroundJobKind.AutomaticSchedule,
+        BackgroundJobKind.SchedulePublish,
+        BackgroundJobKind.MakeupExamAuto,
+        BackgroundJobKind.ExamArrangement,
+        BackgroundJobKind.ExamSignInExport,
+        BackgroundJobKind.ExamPublish
+    ];
+
+    public static async Task<IConnection> CreateConnectionAsync(
+        RabbitMqOptions options,
+        string clientName,
+        ushort consumerDispatchConcurrency,
+        CancellationToken cancellationToken)
+    {
+        var factory = new ConnectionFactory
+        {
+            HostName = options.HostName,
+            Port = options.Port,
+            UserName = options.UserName,
+            Password = options.Password,
+            VirtualHost = options.VirtualHost,
+            ClientProvidedName = clientName,
+            AutomaticRecoveryEnabled = false,
+            TopologyRecoveryEnabled = false,
+            RequestedHeartbeat = TimeSpan.FromSeconds(30),
+            ConsumerDispatchConcurrency = consumerDispatchConcurrency
+        };
+        if (options.UseTls)
+        {
+            factory.Ssl = new SslOption
+            {
+                Enabled = true,
+                ServerName = string.IsNullOrWhiteSpace(options.TlsServerName)
+                    ? options.HostName
+                    : options.TlsServerName
+            };
+        }
+
+        return await factory.CreateConnectionAsync(cancellationToken);
+    }
+
+    public static async Task DeclareAsync(
+        IChannel channel,
+        BackgroundJobOptions options,
+        CancellationToken cancellationToken)
+    {
+        var deadExchange = options.Exchange + ".dead";
+        await channel.ExchangeDeclareAsync(
+            options.Exchange,
+            ExchangeType.Direct,
+            durable: true,
+            autoDelete: false,
+            cancellationToken: cancellationToken);
+        await channel.ExchangeDeclareAsync(
+            deadExchange,
+            ExchangeType.Direct,
+            durable: true,
+            autoDelete: false,
+            cancellationToken: cancellationToken);
+
+        foreach (var kind in JobKinds)
+        {
+            var routingKey = RoutingKey(kind);
+            var queueName = QueueName(options, kind);
+            var deadQueueName = queueName + ".dead";
+            var queueArguments = QueueArguments(options);
+            queueArguments["x-dead-letter-exchange"] = deadExchange;
+            queueArguments["x-dead-letter-routing-key"] = routingKey;
+            await channel.QueueDeclareAsync(
+                queueName,
+                durable: true,
+                exclusive: false,
+                autoDelete: false,
+                arguments: queueArguments,
+                cancellationToken: cancellationToken);
+            await channel.QueueBindAsync(
+                queueName,
+                options.Exchange,
+                routingKey,
+                cancellationToken: cancellationToken);
+
+            await channel.QueueDeclareAsync(
+                deadQueueName,
+                durable: true,
+                exclusive: false,
+                autoDelete: false,
+                arguments: QueueArguments(options),
+                cancellationToken: cancellationToken);
+            await channel.QueueBindAsync(
+                deadQueueName,
+                deadExchange,
+                routingKey,
+                cancellationToken: cancellationToken);
+        }
+    }
+
+    public static string RoutingKey(BackgroundJobKind kind) => kind switch
+    {
+        BackgroundJobKind.AutomaticSchedule => "schedule.automatic",
+        BackgroundJobKind.SchedulePublish => "schedule.publish",
+        BackgroundJobKind.MakeupExamAuto => "makeup-exam.automatic",
+        BackgroundJobKind.ExamArrangement => "exam.arrangement",
+        BackgroundJobKind.ExamSignInExport => "exam.sign-in-export",
+        BackgroundJobKind.ExamPublish => "exam.publish",
+        _ => throw new ArgumentOutOfRangeException(nameof(kind), kind, null)
+    };
+
+    public static string QueueName(
+        BackgroundJobOptions options,
+        BackgroundJobKind kind) =>
+        $"{options.QueuePrefix}.{RoutingKey(kind)}";
+
+    private static Dictionary<string, object?> QueueArguments(
+        BackgroundJobOptions options)
+    {
+        var arguments = new Dictionary<string, object?>();
+        if (options.UseQuorumQueues)
+            arguments["x-queue-type"] = "quorum";
+        return arguments;
+    }
+}

src/Jiaowu.Api/Infrastructure/Caching/AppCache.cs

@@ -0,0 +1,196 @@
+using Microsoft.Extensions.Caching.Hybrid;
+using StackExchange.Redis;
+
+namespace Jiaowu.Api.Infrastructure.Caching;
+
+public enum AppCacheProfile
+{
+    ReferenceData,
+    PublishedTimetable,
+    Analytics
+}
+
+public interface IAppCache
+{
+    Task<T> GetOrCreateAsync<T>(
+        string key,
+        Func<CancellationToken, Task<T>> factory,
+        AppCacheProfile profile,
+        IReadOnlyCollection<string> tags,
+        CancellationToken cancellationToken);
+
+    ValueTask RemoveByTagAsync(
+        string tag,
+        CancellationToken cancellationToken = default);
+}
+
+public sealed class HybridAppCache(
+    HybridCache cache,
+    AppCacheOptions options,
+    IHostEnvironment environment,
+    ILogger<HybridAppCache> logger) : IAppCache
+{
+    private readonly string prefix = BuildPrefix(options.KeyPrefix, environment.EnvironmentName);
+
+    public async Task<T> GetOrCreateAsync<T>(
+        string key,
+        Func<CancellationToken, Task<T>> factory,
+        AppCacheProfile profile,
+        IReadOnlyCollection<string> tags,
+        CancellationToken cancellationToken)
+    {
+        if (!options.Enabled)
+            return await factory(cancellationToken);
+
+        var sourceCompleted = false;
+        T? sourceValue = default;
+        try
+        {
+            return await cache.GetOrCreateAsync(
+                $"{prefix}:{key}",
+                async token =>
+                {
+                    sourceValue = await factory(token);
+                    sourceCompleted = true;
+                    return sourceValue;
+                },
+                GetEntryOptions(profile),
+                tags.Select(tag => $"{prefix}:tag:{tag}"),
+                cancellationToken);
+        }
+        catch (RedisException exception)
+        {
+            logger.LogWarning(
+                exception,
+                "Redis cache operation failed for {CacheKey}; using the source directly.",
+                key);
+            if (sourceCompleted)
+                return sourceValue!;
+            return await factory(cancellationToken);
+        }
+    }
+
+    public async ValueTask RemoveByTagAsync(
+        string tag,
+        CancellationToken cancellationToken = default)
+    {
+        if (!options.Enabled)
+            return;
+
+        try
+        {
+            await cache.RemoveByTagAsync(
+                $"{prefix}:tag:{tag}",
+                cancellationToken);
+        }
+        catch (RedisException exception)
+        {
+            logger.LogWarning(
+                exception,
+                "Redis cache invalidation failed for tag {CacheTag}; TTL will bound staleness.",
+                tag);
+        }
+    }
+
+    private HybridCacheEntryOptions GetEntryOptions(AppCacheProfile profile) =>
+        profile switch
+        {
+            AppCacheProfile.ReferenceData => new HybridCacheEntryOptions
+            {
+                Expiration = TimeSpan.FromMinutes(options.ReferenceExpirationMinutes),
+                LocalCacheExpiration =
+                    TimeSpan.FromSeconds(options.ReferenceLocalExpirationSeconds)
+            },
+            AppCacheProfile.PublishedTimetable => new HybridCacheEntryOptions
+            {
+                Expiration = TimeSpan.FromMinutes(options.TimetableExpirationMinutes),
+                LocalCacheExpiration =
+                    TimeSpan.FromSeconds(options.TimetableLocalExpirationSeconds)
+            },
+            AppCacheProfile.Analytics => new HybridCacheEntryOptions
+            {
+                Expiration = TimeSpan.FromMinutes(options.AnalyticsExpirationMinutes),
+                LocalCacheExpiration =
+                    TimeSpan.FromSeconds(options.AnalyticsLocalExpirationSeconds)
+            },
+            _ => throw new ArgumentOutOfRangeException(nameof(profile), profile, null)
+        };
+
+    private static string BuildPrefix(string configuredPrefix, string environmentName)
+    {
+        var prefixValue = string.IsNullOrWhiteSpace(configuredPrefix)
+            ? "jiaowu:v1"
+            : configuredPrefix.Trim().Trim(':');
+        var environmentValue = string.Concat(
+            environmentName.Trim().ToLowerInvariant()
+                .Select(character => char.IsLetterOrDigit(character) ? character : '-'));
+        return $"{prefixValue}:{environmentValue}";
+    }
+}
+
+public sealed class NoOpAppCache : IAppCache
+{
+    public static NoOpAppCache Instance { get; } = new();
+
+    private NoOpAppCache()
+    {
+    }
+
+    public Task<T> GetOrCreateAsync<T>(
+        string key,
+        Func<CancellationToken, Task<T>> factory,
+        AppCacheProfile profile,
+        IReadOnlyCollection<string> tags,
+        CancellationToken cancellationToken) =>
+        factory(cancellationToken);
+
+    public ValueTask RemoveByTagAsync(
+        string tag,
+        CancellationToken cancellationToken = default) =>
+        ValueTask.CompletedTask;
+}
+
+public static class AppCacheKeys
+{
+    public const string ActivationOptions = "auth:activation-options";
+    public const string Dashboard = "dashboard:summary";
+    public const string TimetableOptions = "timetable:options";
+
+    public static string BaseData(string kind) => $"base-data:{kind}";
+
+    public static string PublishedTimetable(
+        string resourceType,
+        Guid resourceId,
+        Guid? academicTermId) =>
+        $"timetable:published:{academicTermId?.ToString("N") ?? "current"}:" +
+        $"{resourceType}:{resourceId:N}";
+
+    public static string Statistics(
+        string area,
+        string dataScope,
+        Guid? effectiveCollegeId,
+        params string?[] filters)
+    {
+        static string Normalize(string? value) =>
+            string.IsNullOrWhiteSpace(value)
+                ? "-"
+                : value.Trim().ToLowerInvariant();
+
+        var filterPart = filters.Length == 0
+            ? "all"
+            : string.Join(':', filters.Select(Normalize));
+        return $"statistics:v2:{Normalize(area)}:scope:{Normalize(dataScope)}:" +
+               $"college:{effectiveCollegeId?.ToString("N") ?? "all"}:{filterPart}";
+    }
+}
+
+public static class AppCacheTags
+{
+    public const string BaseData = "base-data";
+    public const string Analytics = "analytics";
+    public const string Timetables = "timetables";
+    public const string TimetableOptions = "timetable:options";
+
+    public static string Timetable(Guid academicTermId) =>
+        $"timetable:term:{academicTermId:N}";
+}

src/Jiaowu.Api/Infrastructure/Caching/AppCacheOptions.cs

@@ -0,0 +1,16 @@
+namespace Jiaowu.Api.Infrastructure.Caching;
+
+public sealed class AppCacheOptions
+{
+    public const string SectionName = "Cache";
+
+    public bool Enabled { get; set; } = true;
+    public string KeyPrefix { get; set; } = "jiaowu:v1";
+    public int ReferenceExpirationMinutes { get; set; } = 30;
+    public int ReferenceLocalExpirationSeconds { get; set; } = 120;
+    public int TimetableExpirationMinutes { get; set; } = 10;
+    public int TimetableLocalExpirationSeconds { get; set; } = 30;
+    public int AnalyticsExpirationMinutes { get; set; } = 3;
+    public int AnalyticsLocalExpirationSeconds { get; set; } = 30;
+    public int MaximumPayloadKilobytes { get; set; } = 2048;
+}

src/Jiaowu.Api/Infrastructure/CourseSelection/CourseSelectionRules.cs

@@ -14,9 +14,23 @@ public static class CourseSelectionRules
         round.Status == CourseSelectionRoundStatus.Open &&
         nowUtc <= round.WithdrawalEndsAt;
 
+    public static bool CanPromoteWaitlist(CourseSelectionRound round, DateTime nowUtc) =>
+        round.Status == CourseSelectionRoundStatus.Open &&
+        nowUtc <= round.WithdrawalEndsAt;
+
     public static bool SupportsProxyEnrollment(CourseNature nature) =>
         nature == CourseNature.GeneralRequired;
 
+    public static bool IsGradeEligible(
+        IEnumerable<int> eligibleGrades,
+        int studentGrade) =>
+        !eligibleGrades.Any() || eligibleGrades.Contains(studentGrade);
+
+    public static bool HasReachedCourseLimit(
+        int? maxCourseCount,
+        int selectedCourseCount) =>
+        maxCourseCount.HasValue && selectedCourseCount >= maxCourseCount.Value;
+
     public static bool RequiresPublishedSchedule(TeachingTaskSchedulingMode schedulingMode) =>
         schedulingMode == TeachingTaskSchedulingMode.Standard;
 
@@ -68,4 +82,7 @@ public static class CourseSelectionRules
     /// <summary>Retake expanded capacity: ceiling(original * 1.15).</summary>
     public static int RetakeCapacity(int originalCapacity) =>
         (int)Math.Ceiling(originalCapacity * 1.15);
+
+    public static int EffectiveCapacity(int originalCapacity, bool isRetake) =>
+        isRetake ? RetakeCapacity(originalCapacity) : originalCapacity;
 }

src/Jiaowu.Api/Infrastructure/Exams/ExamArrangementJobs.cs

@@ -0,0 +1,126 @@
+using System.Text.Json;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.Exams;
+
+public sealed class ExamArrangementJobProcessor(
+    AppDbContext db,
+    ExamArrangementService examArrangementService,
+    MakeupExamArrangementService makeupExamArrangementService,
+    IAppCache cache,
+    ILogger<ExamArrangementJobProcessor> logger)
+{
+    public async Task ProcessAsync(Guid jobId, CancellationToken stoppingToken)
+    {
+        try
+        {
+            var job = await db.ExamArrangementJobs
+                .FirstOrDefaultAsync(x => x.Id == jobId, stoppingToken);
+            if (job is null ||
+                job.Status is ExamArrangementJobStatus.Succeeded
+                    or ExamArrangementJobStatus.Failed)
+            {
+                return;
+            }
+
+            job.Status = ExamArrangementJobStatus.Running;
+            job.StartedAt ??= DateTime.UtcNow;
+            job.CompletedAt = null;
+            job.ErrorMessage = null;
+            job.ResultMessage = null;
+            job.CurrentStep = job.Kind == ExamArrangementKind.FormalExam
+                ? "正在编排正式考试"
+                : "正在编排补考";
+            await db.SaveChangesAsync(stoppingToken);
+
+            var sessionIds = DeserializeSessionIds(job.SessionIdsJson);
+            var result = job.Kind switch
+            {
+                ExamArrangementKind.FormalExam =>
+                    await examArrangementService.ArrangeAsync(
+                        job.PlanId,
+                        sessionIds,
+                        job.AssignClassrooms,
+                        job.AssignInvigilators,
+                        stoppingToken),
+                ExamArrangementKind.MakeupExam =>
+                    await makeupExamArrangementService.ArrangeAsync(
+                        job.PlanId,
+                        sessionIds,
+                        job.AssignClassrooms,
+                        job.AssignInvigilators,
+                        stoppingToken),
+                _ => throw new InvalidOperationException(
+                    $"不支持的考试编排类型：{job.Kind}。")
+            };
+
+            if (!result.Success)
+            {
+                await MarkFailedAsync(jobId, result.Message);
+                return;
+            }
+
+            job.Status = ExamArrangementJobStatus.Succeeded;
+            job.ProcessedSessions = job.TotalSessions;
+            job.CurrentStep = "编排完成";
+            job.ResultMessage = result.Message;
+            job.ActivePlanId = null;
+            job.CompletedAt = DateTime.UtcNow;
+            await db.SaveChangesAsync(stoppingToken);
+
+            if (job.Kind == ExamArrangementKind.FormalExam)
+            {
+                await cache.RemoveByTagAsync(
+                    AppCacheTags.Timetables,
+                    stoppingToken);
+            }
+
+            logger.LogInformation(
+                "Exam arrangement job {JobId} for {Kind}/{PlanId} completed.",
+                job.Id,
+                job.Kind,
+                job.PlanId);
+        }
+        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+        {
+            logger.LogInformation(
+                "Exam arrangement job {JobId} was interrupted by application shutdown.",
+                jobId);
+            throw;
+        }
+        catch (Exception exception)
+        {
+            logger.LogError(exception, "Exam arrangement job {JobId} failed.", jobId);
+            await MarkFailedAsync(jobId, exception.GetBaseException().Message);
+        }
+    }
+
+    private static IReadOnlyCollection<Guid>? DeserializeSessionIds(string? json)
+    {
+        if (string.IsNullOrWhiteSpace(json))
+            return null;
+
+        var sessionIds = JsonSerializer.Deserialize<Guid[]>(json);
+        return sessionIds is { Length: > 0 } ? sessionIds : null;
+    }
+
+    private async Task MarkFailedAsync(Guid jobId, string message)
+    {
+        db.ChangeTracker.Clear();
+        var job = await db.ExamArrangementJobs.FirstOrDefaultAsync(
+            x => x.Id == jobId,
+            CancellationToken.None);
+        if (job is null)
+            return;
+
+        job.Status = ExamArrangementJobStatus.Failed;
+        job.ActivePlanId = null;
+        job.CurrentStep = "编排失败";
+        job.ErrorMessage = message.Length <= 2000 ? message : message[..2000];
+        job.CompletedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(CancellationToken.None);
+    }
+}

src/Jiaowu.Api/Infrastructure/Exams/ExamArrangementService.cs

@@ -1,18 +1,44 @@
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Teaching;
 using Microsoft.EntityFrameworkCore;
 
 namespace Jiaowu.Api.Infrastructure.Exams;
 
 public sealed class ExamArrangementService(AppDbContext db)
 {
-    private sealed record RoomOccupancy(Guid ClassroomId, DateTime StartsAt, DateTime EndsAt);
+    private sealed record RoomGroupKey(
-    private sealed record InvigilatorOccupancy(Guid TeacherId, DateTime StartsAt, DateTime EndsAt);
+        Guid CourseId,
+        DateOnly ExamDate,
+        int StartPeriod,
+        int PeriodCount,
+        string RequiredBuildingIdsKey);
+
+    private sealed record RoomOccupancy(
+        Guid ClassroomId,
+        DateTime StartsAt,
+        DateTime EndsAt);
+
+    private sealed record InvigilatorOccupancy(
+        Guid TeacherId,
+        DateTime StartsAt,
+        DateTime EndsAt);
+
+    private sealed record CandidateSeat(
+        Guid ExamSessionId,
+        Guid StudentId,
+        string StudentNumber);
 
     public async Task<ExamArrangementResult> ArrangeAsync(
         Guid planId,
+        IReadOnlyCollection<Guid>? requestedSessionIds,
+        bool assignClassrooms,
+        bool assignInvigilators,
         CancellationToken cancellationToken)
     {
+        if (!assignClassrooms && !assignInvigilators)
+            return ExamArrangementResult.Fail("请至少选择分配考场或分配监考教师。");
+
         var plan = await db.ExamPlans
             .Include(x => x.AcademicTerm)
             .Include(x => x.Sessions)
@@ -20,6 +46,16 @@ public sealed class ExamArrangementService(AppDbContext db)
             .Include(x => x.Sessions)
                 .ThenInclude(x => x.TeachingTask)
                     .ThenInclude(x => x!.Teachers)
+            .Include(x => x.Sessions)
+                .ThenInclude(x => x.TeachingTask)
+                    .ThenInclude(x => x!.Course)
+            .Include(x => x.Rooms)
+                .ThenInclude(x => x.SessionLinks)
+            .Include(x => x.Rooms)
+                .ThenInclude(x => x.Seats)
+            .Include(x => x.Rooms)
+                .ThenInclude(x => x.Invigilators)
+            .AsSplitQuery()
             .FirstOrDefaultAsync(x => x.Id == planId, cancellationToken);
 
         if (plan is null)
@@ -27,201 +63,558 @@ public sealed class ExamArrangementService(AppDbContext db)
         if (plan.Status != ExamPlanStatus.Draft)
             return ExamArrangementResult.Fail("只有草稿状态的考试计划可以自动编排。");
 
-        var sessions = plan.Sessions.ToList();
+        var requestedIds = (requestedSessionIds ?? [])
-        if (sessions.Count == 0)
+            .Distinct()
-            return ExamArrangementResult.Fail("考试计划中没有场次。");
+            .ToHashSet();
+        if (requestedIds.Count > 100)
+            return ExamArrangementResult.Fail("一次最多处理100个考试场次。");
+        if (requestedIds.Count > 0 &&
+            plan.Sessions.Count(x => requestedIds.Contains(x.Id)) != requestedIds.Count)
+            return ExamArrangementResult.Fail("所选场次不存在或不属于当前考试计划。");
 
-        var termId = plan.AcademicTermId;
         var timeSlots = await db.ScheduleTimeSlots.AsNoTracking()
-            .Where(x => x.AcademicTermId == termId && x.IsEnabled)
+            .Where(x => x.AcademicTermId == plan.AcademicTermId && x.IsEnabled)
             .OrderBy(x => x.PeriodNumber)
             .ToListAsync(cancellationToken);
-
         if (timeSlots.Count == 0)
             return ExamArrangementResult.Fail("当前学期未配置上课时间表，无法计算考试时间段。");
 
         var timeSlotLookup = timeSlots.ToDictionary(x => x.PeriodNumber);
+        foreach (var session in plan.Sessions)
+            ComputeTimesFromSlots(session, timeSlotLookup);
 
-        int assignedRooms = 0;
+        var explicitlySelected = plan.Sessions
-        int assignedInvigilators = 0;
+            .Where(x => requestedIds.Count == 0 || requestedIds.Contains(x.Id))
-        int skippedRooms = 0;
+            .ToList();
-        int skippedInvigilators = 0;
+        if (explicitlySelected.Count == 0)
+            return ExamArrangementResult.Fail("没有可处理的考试场次。");
+
+        var selectedKeys = explicitlySelected
+            .Select(GroupKey)
+            .ToHashSet();
+        var sessions = plan.Sessions
+            .Where(x => selectedKeys.Contains(GroupKey(x)))
+            .OrderBy(x => x.ExamDate)
+            .ThenBy(x => x.StartPeriod)
+            .ThenBy(x => x.TeachingTask!.Course!.Code)
+            .ThenBy(x => x.TeachingTask!.TaskNumber)
+            .ToList();
+        var sessionIds = sessions.Select(x => x.Id).ToHashSet();
+
+        var roster = await TeachingTaskRosterQuery.LoadForTasksAsync(
+            db,
+            sessions.Select(x => x.TeachingTaskId),
+            cancellationToken);
+        var sessionByTaskId = sessions
+            .GroupBy(x => x.TeachingTaskId)
+            .ToDictionary(x => x.Key, x => x.First());
+
+        var replacedRooms = assignClassrooms
+            ? plan.Rooms
+                .Where(room => room.SessionLinks.Any(link =>
+                    sessionIds.Contains(link.ExamSessionId)))
+                .ToList()
+            : [];
+        var replacedRoomIds = replacedRooms.Select(x => x.Id).ToHashSet();
+        if (replacedRooms.Count > 0)
+            db.ExamRooms.RemoveRange(replacedRooms);
+
+        var occupiedRooms = await LoadOccupiedRoomsAsync(
+            plan,
+            sessionIds,
+            replacedRoomIds,
+            cancellationToken);
+        var rooms = await db.Classrooms.AsNoTracking()
+            .Include(x => x.Building)
+            .Where(x => x.IsEnabled)
+            .OrderBy(x => x.Building!.Name)
+            .ThenBy(x => x.Name)
+            .ToListAsync(cancellationToken);
+
+        var targetRooms = new List<ExamRoomAssignment>();
         var messages = new List<string>();
+        var seatedStudents = 0;
+        var unavailableStudents = 0;
 
-        // Track occupied time slots to avoid conflicts
+        if (assignClassrooms)
-        var occupiedRooms = sessions
+        {
-            .Where(x => x.ClassroomId.HasValue)
-            .Select(x => new RoomOccupancy(x.ClassroomId!.Value, x.StartsAt, x.EndsAt))
-            .ToList();
-
-        var occupiedInvigilators = sessions
-            .SelectMany(x => x.Invigilators.Select(i =>
-                new InvigilatorOccupancy(i.TeacherId, x.StartsAt, x.EndsAt)))
-            .ToList();
-
             foreach (var session in sessions)
             {
-            // Compute StartsAt/EndsAt from time slots
+                session.ClassroomId = null;
-            ComputeTimesFromSlots(session, timeSlotLookup);
+                if (session.Invigilators.Count > 0)
-            var studentCount = await db.CourseEnrollments.CountAsync(
+                {
-                x => x.Status == CourseEnrollmentStatus.Enrolled &&
+                    db.ExamSessionInvigilators.RemoveRange(session.Invigilators);
-                     x.CourseSelectionOffering!.TeachingTaskId == session.TeachingTaskId,
+                    session.Invigilators.Clear();
+                }
+            }
+
+            foreach (var group in sessions
+                         .GroupBy(GroupKey)
+                         .OrderBy(x => x.Key.ExamDate)
+                         .ThenBy(x => x.Key.StartPeriod)
+                         .ThenBy(x => x.First().TeachingTask!.Course!.Code))
+            {
+                var groupSessions = group.ToList();
+                var candidates = InterleaveCandidates(
+                    groupSessions,
+                    roster,
+                    sessionByTaskId);
+                if (candidates.Count == 0)
+                {
+                    messages.Add(
+                        $"“{groupSessions[0].TeachingTask!.Course!.Name}”没有有效考生。");
+                    continue;
+                }
+
+                var availableRooms = rooms
+                    .Where(room =>
+                        (group.Key.RequiredBuildingIdsKey.Length == 0 ||
+                         group.Key.RequiredBuildingIdsKey
+                             .Split(',', StringSplitOptions.RemoveEmptyEntries)
+                             .Contains(room.BuildingId.ToString())) &&
+                        occupiedRooms.All(occupied =>
+                            occupied.ClassroomId != room.Id ||
+                            !ExamConflictRules.TimeOverlaps(
+                                occupied.StartsAt,
+                                occupied.EndsAt,
+                                groupSessions[0].StartsAt,
+                                groupSessions[0].EndsAt)))
+                    .ToList();
+                var selectedRooms = SelectRooms(
+                    availableRooms,
+                    candidates.Count);
+                if (selectedRooms.Sum(x => x.Capacity / 2) < candidates.Count)
+                {
+                    unavailableStudents += candidates.Count;
+                    messages.Add(
+                        $"“{groupSessions[0].TeachingTask!.Course!.Name}”缺少足够考场容量，" +
+                        $"需 {candidates.Count} 座、可用 {selectedRooms.Sum(x => x.Capacity / 2)} 座。");
+                    continue;
+                }
+
+                var offset = 0;
+                foreach (var classroom in selectedRooms)
+                {
+                    var roomCandidates = candidates
+                        .Skip(offset)
+                        .Take(classroom.Capacity / 2)
+                        .ToList();
+                    if (roomCandidates.Count == 0) break;
+                    offset += roomCandidates.Count;
+
+                    var room = new ExamRoomAssignment
+                    {
+                        ExamPlanId = plan.Id,
+                        CourseId = group.Key.CourseId,
+                        ClassroomId = classroom.Id,
+                        ExamDate = group.Key.ExamDate,
+                        StartPeriod = group.Key.StartPeriod,
+                        PeriodCount = group.Key.PeriodCount,
+                        StartsAt = groupSessions[0].StartsAt,
+                        EndsAt = groupSessions[0].EndsAt,
+                        RequiredInvigilatorCount =
+                            groupSessions.Max(x => x.RequiredInvigilatorCount),
+                        SessionLinks = roomCandidates
+                            .Select(x => x.ExamSessionId)
+                            .Distinct()
+                            .Select(sessionId => new ExamRoomSession
+                            {
+                                ExamSessionId = sessionId
+                            })
+                            .ToList(),
+                        Seats = roomCandidates
+                            .Select((candidate, index) =>
+                                new ExamSeatAssignment
+                                {
+                                    ExamSessionId = candidate.ExamSessionId,
+                                    StudentId = candidate.StudentId,
+                                    SeatNumber = index + 1
+                                })
+                            .ToList()
+                    };
+                    db.ExamRooms.Add(room);
+                    targetRooms.Add(room);
+                    occupiedRooms.Add(new RoomOccupancy(
+                        classroom.Id,
+                        room.StartsAt,
+                        room.EndsAt));
+                    seatedStudents += roomCandidates.Count;
+                }
+
+                messages.Add(
+                    $"“{groupSessions[0].TeachingTask!.Course!.Name}”" +
+                    $"{groupSessions.Count}个教学班混排至{selectedRooms.Count}个考场。");
+            }
+        }
+        else
+        {
+            targetRooms.AddRange(plan.Rooms.Where(room =>
+                room.SessionLinks.Any(link =>
+                    sessionIds.Contains(link.ExamSessionId))));
+            var linkedSessionIds = targetRooms
+                .SelectMany(x => x.SessionLinks)
+                .Select(x => x.ExamSessionId)
+                .ToHashSet();
+            foreach (var session in sessions.Where(x =>
+                         !linkedSessionIds.Contains(x.Id) &&
+                         x.ClassroomId.HasValue))
+            {
+                var legacyRoom = CreateLegacyRoom(
+                    plan,
+                    session,
+                    roster.Where(x =>
+                        x.TeachingTaskId == session.TeachingTaskId));
+                db.ExamRooms.Add(legacyRoom);
+                targetRooms.Add(legacyRoom);
+                session.ClassroomId = null;
+                if (session.Invigilators.Count > 0)
+                {
+                    db.ExamSessionInvigilators.RemoveRange(session.Invigilators);
+                    session.Invigilators.Clear();
+                }
+            }
+            seatedStudents = targetRooms.Sum(x => x.Seats.Count);
+        }
+
+        var assignedInvigilators = 0;
+        var unavailableInvigilators = 0;
+        if (assignInvigilators)
+        {
+            if (targetRooms.Count == 0)
+                return ExamArrangementResult.Fail("尚未生成实际考场，请先分配考场。");
+
+            var occupiedInvigilators = plan.Rooms
+                .Where(x => !replacedRoomIds.Contains(x.Id) &&
+                            !targetRooms.Any(target => target.Id == x.Id))
+                .SelectMany(room => room.Invigilators.Select(item =>
+                    new InvigilatorOccupancy(
+                        item.TeacherId,
+                        room.StartsAt,
+                        room.EndsAt)))
+                .Concat(plan.Sessions
+                    .Where(x => !sessionIds.Contains(x.Id))
+                    .SelectMany(session => session.Invigilators.Select(item =>
+                        new InvigilatorOccupancy(
+                            item.TeacherId,
+                            session.StartsAt,
+                            session.EndsAt))))
+                .ToList();
+
+            foreach (var room in targetRooms
+                         .OrderBy(x => x.ExamDate)
+                         .ThenBy(x => x.StartPeriod)
+                         .ThenBy(x => x.ClassroomId))
+            {
+                var needed = room.RequiredInvigilatorCount -
+                             room.Invigilators.Count;
+                if (needed <= 0) continue;
+
+                var linkedSessionIds = room.SessionLinks
+                    .Select(x => x.ExamSessionId)
+                    .ToHashSet();
+                var excludedTeacherIds = sessions
+                    .Where(x => linkedSessionIds.Contains(x.Id))
+                    .SelectMany(x => x.TeachingTask!.Teachers)
+                    .Select(x => x.TeacherId)
+                    .ToHashSet();
+                var teachers = await FindInvigilatorsAsync(
+                    room,
+                    needed,
+                    excludedTeacherIds,
+                    occupiedInvigilators,
                     cancellationToken);
-
+                foreach (var teacher in teachers)
-            // ── Auto-assign classroom ──
-            if (!session.ClassroomId.HasValue)
                 {
-                var room = await FindBestClassroomAsync(
+                    room.Invigilators.Add(new ExamRoomInvigilator
-                    session, studentCount, occupiedRooms, cancellationToken);
-                if (room is not null)
                     {
-                    session.ClassroomId = room.Id;
-                    occupiedRooms.Add(new RoomOccupancy(room.Id, session.StartsAt, session.EndsAt));
-                    assignedRooms++;
-                    messages.Add(
-                        $"“{session.TeachingTask!.Course!.Name}”→{room.Name}({room.Capacity}座)");
-                }
-                else
-                {
-                    skippedRooms++;
-                    messages.Add(
-                        $"“{session.TeachingTask!.Course!.Name}”：无可用考场（需≥{studentCount}座）");
-                }
-            }
-            else
-            {
-                skippedRooms++;
-            }
-
-            // ── Auto-assign invigilators ──
-            var currentInvigilatorCount = session.Invigilators.Count;
-            var needed = session.RequiredInvigilatorCount - currentInvigilatorCount;
-            if (needed > 0)
-            {
-                var courseTeacherIds = session.TeachingTask!.Teachers
-                    .Select(x => x.TeacherId).ToHashSet();
-                var newlyAssigned = await FindInvigilatorsAsync(
-                    session, needed, courseTeacherIds,
-                    occupiedInvigilators, cancellationToken);
-                foreach (var teacher in newlyAssigned)
-                {
-                    session.Invigilators.Add(new ExamSessionInvigilator
-                    {
-                        ExamSessionId = session.Id,
                         TeacherId = teacher.Id
                     });
                     occupiedInvigilators.Add(new InvigilatorOccupancy(
-                        teacher.Id, session.StartsAt, session.EndsAt));
+                        teacher.Id,
+                        room.StartsAt,
+                        room.EndsAt));
                     assignedInvigilators++;
                 }
 
-                if (newlyAssigned.Count < needed)
+                if (teachers.Count < needed)
-                    messages.Add(
+                    unavailableInvigilators += needed - teachers.Count;
-                        $"“{session.TeachingTask!.Course!.Name}”：仅找到{newlyAssigned.Count}/{needed}名监考教师");
-            }
-            else
-            {
-                skippedInvigilators++;
             }
         }
 
         await db.SaveChangesAsync(cancellationToken);
 
+        var expandedCount = sessions.Count - explicitlySelected.Count;
+        var detail = messages.Count > 0
+            ? $" 详情：{string.Join("；", messages.Take(10))}"
+            : "";
         return new ExamArrangementResult(
             true,
-            $"{assignedRooms}个考场、{assignedInvigilators}名监考已分配。" +
+            $"{sessions.Count}个教学班场次处理完成，生成{targetRooms.Count}个实际考场，" +
-            (skippedRooms > 0 ? $" {skippedRooms}个场次无可用考场。" : "") +
+            $"安排{seatedStudents}名考生、{assignedInvigilators}名监考教师。" +
-            (messages.Count > 0 ? $" 详情：{string.Join("；", messages.Take(10))}" : ""));
+            (expandedCount > 0
+                ? $" 为保持混排完整性，自动包含同组{expandedCount}个场次。"
+                : "") +
+            (unavailableStudents > 0
+                ? $" {unavailableStudents}名考生尚未安排考场。"
+                : "") +
+            (unavailableInvigilators > 0
+                ? $" 仍缺{unavailableInvigilators}名监考教师。"
+                : "") +
+            detail);
+    }
+
+    private async Task<List<RoomOccupancy>> LoadOccupiedRoomsAsync(
+        ExamPlan plan,
+        IReadOnlySet<Guid> targetSessionIds,
+        IReadOnlySet<Guid> replacedRoomIds,
+        CancellationToken cancellationToken)
+    {
+        var occupied = plan.Rooms
+            .Where(x => !replacedRoomIds.Contains(x.Id))
+            .Select(x => new RoomOccupancy(
+                x.ClassroomId,
+                x.StartsAt,
+                x.EndsAt))
+            .ToList();
+        occupied.AddRange(plan.Sessions
+            .Where(x =>
+                !targetSessionIds.Contains(x.Id) &&
+                x.ClassroomId.HasValue)
+            .Select(x => new RoomOccupancy(
+                x.ClassroomId!.Value,
+                x.StartsAt,
+                x.EndsAt)));
+
+        var externalRooms = await db.ExamRooms.AsNoTracking()
+            .Where(x =>
+                x.ExamPlanId != plan.Id &&
+                x.ExamPlan!.Status != ExamPlanStatus.Archived)
+            .Select(x => new RoomOccupancy(
+                x.ClassroomId,
+                x.StartsAt,
+                x.EndsAt))
+            .ToListAsync(cancellationToken);
+        occupied.AddRange(externalRooms);
+
+        var externalLegacyRooms = await db.ExamSessions.AsNoTracking()
+            .Where(x =>
+                x.ExamPlanId != plan.Id &&
+                x.ExamPlan!.Status != ExamPlanStatus.Archived &&
+                x.ClassroomId != null)
+            .Select(x => new RoomOccupancy(
+                x.ClassroomId!.Value,
+                x.StartsAt,
+                x.EndsAt))
+            .ToListAsync(cancellationToken);
+        occupied.AddRange(externalLegacyRooms);
+        return occupied;
+    }
+
+    private async Task<List<Teacher>> FindInvigilatorsAsync(
+        ExamRoomAssignment room,
+        int needed,
+        HashSet<Guid> excludedTeacherIds,
+        List<InvigilatorOccupancy> occupied,
+        CancellationToken cancellationToken)
+    {
+        var busyTeacherIds = occupied
+            .Where(x => ExamConflictRules.TimeOverlaps(
+                x.StartsAt,
+                x.EndsAt,
+                room.StartsAt,
+                room.EndsAt))
+            .Select(x => x.TeacherId)
+            .ToHashSet();
+
+        var databaseBusyIds = await db.ExamRoomInvigilators.AsNoTracking()
+            .Where(x =>
+                x.ExamRoomId != room.Id &&
+                x.ExamRoom!.ExamPlan!.Status != ExamPlanStatus.Archived &&
+                x.ExamRoom.StartsAt < room.EndsAt &&
+                room.StartsAt < x.ExamRoom.EndsAt)
+            .Select(x => x.TeacherId)
+            .ToListAsync(cancellationToken);
+        foreach (var teacherId in databaseBusyIds)
+            busyTeacherIds.Add(teacherId);
+
+        var legacyBusyIds = await db.ExamSessionInvigilators.AsNoTracking()
+            .Where(x =>
+                x.ExamSession!.ExamPlan!.Status != ExamPlanStatus.Archived &&
+                x.ExamSession.StartsAt < room.EndsAt &&
+                room.StartsAt < x.ExamSession.EndsAt)
+            .Select(x => x.TeacherId)
+            .ToListAsync(cancellationToken);
+        foreach (var teacherId in legacyBusyIds)
+            busyTeacherIds.Add(teacherId);
+        foreach (var teacherId in excludedTeacherIds)
+            busyTeacherIds.Add(teacherId);
+
+        var candidates = await InvigilatorCandidateQuery
+            .Create(db, busyTeacherIds)
+            .ToListAsync(cancellationToken);
+        return candidates
+            .OrderBy(_ => Random.Shared.Next())
+            .Take(needed)
+            .ToList();
+    }
+
+    private static List<Classroom> SelectRooms(
+        IReadOnlyCollection<Classroom> availableRooms,
+        int candidateCount)
+    {
+        var remainingRooms = availableRooms.ToList();
+        var selected = new List<Classroom>();
+        var remainingSeats = candidateCount;
+        while (remainingSeats > 0 && remainingRooms.Count > 0)
+        {
+            var room = remainingRooms
+                           .Where(x => x.Capacity / 2 >= remainingSeats)
+                           .OrderBy(x => x.Capacity / 2)
+                           .ThenBy(x => x.Name)
+                           .FirstOrDefault()
+                       ?? remainingRooms
+                           .OrderByDescending(x => x.Capacity / 2)
+                           .ThenBy(x => x.Name)
+                           .First();
+            selected.Add(room);
+            remainingRooms.Remove(room);
+            remainingSeats -= room.Capacity / 2;
+        }
+        return selected;
+    }
+
+    private static List<CandidateSeat> InterleaveCandidates(
+        IReadOnlyCollection<ExamSession> sessions,
+        IReadOnlyCollection<TeachingTaskRosterEntry> roster,
+        IReadOnlyDictionary<Guid, ExamSession> sessionByTaskId)
+    {
+        var sessionIds = sessions.Select(x => x.Id).ToHashSet();
+        var queues = roster
+            .Where(x =>
+                sessionByTaskId.TryGetValue(
+                    x.TeachingTaskId,
+                    out var session) &&
+                sessionIds.Contains(session.Id))
+            .GroupBy(x => x.TeachingTaskId)
+            .OrderBy(x => sessionByTaskId[x.Key].TeachingTask!.TaskNumber)
+            .Select(group => new Queue<CandidateSeat>(
+                group.OrderBy(x => x.StudentNumber)
+                    .Select(x => new CandidateSeat(
+                        sessionByTaskId[x.TeachingTaskId].Id,
+                        x.StudentId,
+                        x.StudentNumber))))
+            .ToList();
+
+        var result = new List<CandidateSeat>();
+        var assignedStudentIds = new HashSet<Guid>();
+        while (queues.Any(x => x.Count > 0))
+        {
+            foreach (var queue in queues)
+            {
+                while (queue.Count > 0)
+                {
+                    var candidate = queue.Dequeue();
+                    if (!assignedStudentIds.Add(candidate.StudentId))
+                        continue;
+                    result.Add(candidate);
+                    break;
+                }
+            }
+        }
+        return result;
+    }
+
+    private static ExamRoomAssignment CreateLegacyRoom(
+        ExamPlan plan,
+        ExamSession session,
+        IEnumerable<TeachingTaskRosterEntry> roster)
+    {
+        var students = roster
+            .OrderBy(x => x.StudentNumber)
+            .ToList();
+        return new ExamRoomAssignment
+        {
+            ExamPlanId = plan.Id,
+            CourseId = session.TeachingTask!.CourseId,
+            ClassroomId = session.ClassroomId!.Value,
+            ExamDate = session.ExamDate,
+            StartPeriod = session.StartPeriod,
+            PeriodCount = session.PeriodCount,
+            StartsAt = session.StartsAt,
+            EndsAt = session.EndsAt,
+            RequiredInvigilatorCount = session.RequiredInvigilatorCount,
+            SessionLinks =
+            [
+                new ExamRoomSession
+                {
+                    ExamSessionId = session.Id
+                }
+            ],
+            Seats = students.Select((student, index) =>
+                new ExamSeatAssignment
+                {
+                    ExamSessionId = session.Id,
+                    StudentId = student.StudentId,
+                    SeatNumber = index + 1
+                }).ToList(),
+            Invigilators = session.Invigilators.Select(x =>
+                new ExamRoomInvigilator
+                {
+                    TeacherId = x.TeacherId
+                }).ToList()
+        };
+    }
+
+    private static RoomGroupKey GroupKey(ExamSession session)
+    {
+        var buildingIds = ParseBuildingIds(session.RequiredBuildingIds);
+        if (session.RequiredBuildingId.HasValue)
+            buildingIds.Add(session.RequiredBuildingId.Value);
+        var key = buildingIds.Count == 0
+            ? string.Empty
+            : string.Join(",", buildingIds.OrderBy(x => x));
+        return new(
+            session.TeachingTask!.CourseId,
+            session.ExamDate,
+            session.StartPeriod,
+            session.PeriodCount,
+            key);
+    }
+
+    private static HashSet<Guid> ParseBuildingIds(string? json)
+    {
+        if (string.IsNullOrWhiteSpace(json))
+            return [];
+        try
+        {
+            return System.Text.Json.JsonSerializer.Deserialize<HashSet<Guid>>(json) ?? [];
+        }
+        catch
+        {
+            return [];
+        }
     }
 
     private static void ComputeTimesFromSlots(
         ExamSession session,
-        Dictionary<int, ScheduleTimeSlot> timeSlotLookup)
+        IReadOnlyDictionary<int, ScheduleTimeSlot> timeSlotLookup)
     {
         var startSlot = timeSlotLookup.GetValueOrDefault(session.StartPeriod);
         var endSlot = timeSlotLookup.GetValueOrDefault(
             session.StartPeriod + session.PeriodCount - 1);
         if (startSlot is null || endSlot is null) return;
 
-        var examDate = session.ExamDate;
+        session.StartsAt = session.ExamDate.ToDateTime(
-        session.StartsAt = examDate.ToDateTime(startSlot.StartsAt, DateTimeKind.Utc);
+            startSlot.StartsAt,
-        session.EndsAt = examDate.ToDateTime(endSlot.EndsAt, DateTimeKind.Utc);
+            DateTimeKind.Utc);
-    }
+        session.EndsAt = session.ExamDate.ToDateTime(
-
+            endSlot.EndsAt,
-    private async Task<Classroom?> FindBestClassroomAsync(
+            DateTimeKind.Utc);
-        ExamSession session,
-        int studentCount,
-        List<RoomOccupancy> occupied,
-        CancellationToken cancellationToken)
-    {
-        var query = db.Classrooms.AsNoTracking()
-            .Where(x => x.IsEnabled && x.Capacity >= studentCount);
-
-        if (session.RequiredBuildingId.HasValue)
-            query = query.Where(x => x.BuildingId == session.RequiredBuildingId.Value);
-
-        // Exclude classrooms already occupied in-memory
-        var occupiedRoomIds = occupied
-            .Where(x => ExamConflictRules.TimeOverlaps(
-                x.StartsAt, x.EndsAt, session.StartsAt, session.EndsAt))
-            .Select(x => x.ClassroomId)
-            .ToHashSet();
-
-        if (occupiedRoomIds.Count > 0)
-            query = query.WhereNotIn(occupiedRoomIds, x => x.Id);
-
-        // Exclude classrooms occupied by DB sessions not yet tracked in memory
-        var dbOccupiedRooms = await db.ExamSessions.AsNoTracking()
-            .Where(x => x.ExamPlanId == session.ExamPlanId &&
-                        x.Id != session.Id &&
-                        x.ClassroomId != null &&
-                        x.StartsAt < session.EndsAt &&
-                        session.StartsAt < x.EndsAt)
-            .Select(x => x.ClassroomId!.Value)
-            .ToListAsync(cancellationToken);
-
-        if (dbOccupiedRooms.Count > 0)
-            query = query.WhereNotIn(dbOccupiedRooms, x => x.Id);
-
-        return await query
-            .OrderBy(x => x.Capacity)
-            .FirstOrDefaultAsync(cancellationToken);
-    }
-
-    private async Task<List<Teacher>> FindInvigilatorsAsync(
-        ExamSession session,
-        int needed,
-        HashSet<Guid> excludeTeacherIds,
-        List<InvigilatorOccupancy> occupied,
-        CancellationToken cancellationToken)
-    {
-        var busyTeacherIds = occupied
-            .Where(x => ExamConflictRules.TimeOverlaps(
-                x.StartsAt, x.EndsAt, session.StartsAt, session.EndsAt))
-            .Select(x => x.TeacherId)
-            .ToHashSet();
-
-        var dbBusyIds = await db.ExamSessionInvigilators.AsNoTracking()
-            .Where(x => x.ExamSession!.ExamPlanId == session.ExamPlanId &&
-                        x.ExamSessionId != session.Id &&
-                        x.ExamSession!.StartsAt < session.EndsAt &&
-                        session.StartsAt < x.ExamSession.EndsAt)
-            .Select(x => x.TeacherId)
-            .ToListAsync(cancellationToken);
-
-        foreach (var id in dbBusyIds) busyTeacherIds.Add(id);
-        foreach (var id in excludeTeacherIds) busyTeacherIds.Add(id);
-
-        return await db.Teachers.AsNoTracking()
-            .Where(x => x.Status == TeacherStatus.Active)
-            .WhereNotIn(busyTeacherIds, x => x.Id)
-            .OrderBy(x => Guid.NewGuid())
-            .Take(needed)
-            .ToListAsync(cancellationToken);
     }
 }
 
 public sealed record ExamArrangementResult(bool Success, string Message)
 {
-    public static ExamArrangementResult Fail(string message) => new(false, message);
+    public static ExamArrangementResult Fail(string message) =>
+        new(false, message);
 }

src/Jiaowu.Api/Infrastructure/Exams/ExamPublishJobs.cs

@@ -0,0 +1,270 @@
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Teaching;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.Exams;
+
+public sealed class ExamPublishJobProcessor(
+    AppDbContext db,
+    IAppCache cache,
+    ILogger<ExamPublishJobProcessor> logger)
+{
+    public async Task ProcessAsync(Guid jobId, CancellationToken stoppingToken)
+    {
+        try
+        {
+            var job = await db.ExamPublishJobs
+                .FirstOrDefaultAsync(x => x.Id == jobId, stoppingToken);
+            if (job is null ||
+                job.Status is ExamPublishJobStatus.Succeeded
+                    or ExamPublishJobStatus.Failed)
+            {
+                return;
+            }
+
+            job.Status = ExamPublishJobStatus.Running;
+            job.StartedAt ??= DateTime.UtcNow;
+            job.CompletedAt = null;
+            job.ErrorMessage = null;
+            job.CurrentStep = "正在校验考试计划";
+            await db.SaveChangesAsync(stoppingToken);
+
+            switch (job.Kind)
+            {
+                case ExamPublishJobKind.FormalExam:
+                    await PublishFormalExamAsync(job, stoppingToken);
+                    break;
+                case ExamPublishJobKind.MakeupExam:
+                    await PublishMakeupExamAsync(job, stoppingToken);
+                    break;
+                default:
+                    throw new InvalidOperationException(
+                        $"不支持的考试发布类型：{job.Kind}。");
+            }
+
+            job.Status = ExamPublishJobStatus.Succeeded;
+            job.ActivePlanId = null;
+            job.CurrentStep = "发布完成";
+            job.CompletedAt = DateTime.UtcNow;
+            await db.SaveChangesAsync(stoppingToken);
+
+            await cache.RemoveByTagAsync(
+                AppCacheTags.Timetables,
+                stoppingToken);
+
+            logger.LogInformation(
+                "Exam publish job {JobId} for {Kind}/{PlanId} completed.",
+                job.Id,
+                job.Kind,
+                job.PlanId);
+        }
+        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+        {
+            logger.LogInformation(
+                "Exam publish job {JobId} was interrupted by application shutdown.",
+                jobId);
+            throw;
+        }
+        catch (ExamPublishValidationException validationException)
+        {
+            logger.LogWarning(
+                validationException,
+                "Exam publish job {JobId} validation failed.",
+                jobId);
+            await MarkFailedAsync(jobId, validationException.Message);
+        }
+        catch (Exception exception)
+        {
+            logger.LogError(exception, "Exam publish job {JobId} failed.", jobId);
+            await MarkFailedAsync(jobId, exception.GetBaseException().Message);
+        }
+    }
+
+    private async Task PublishFormalExamAsync(
+        ExamPublishJob job,
+        CancellationToken ct)
+    {
+        var plan = await db.ExamPlans
+            .FirstOrDefaultAsync(x => x.Id == job.PlanId, ct);
+        if (plan is null)
+            throw new ExamPublishValidationException("考试计划不存在。");
+        if (plan.Status != ExamPlanStatus.Draft)
+            throw new ExamPublishValidationException("只有草稿考试计划可以发布。");
+
+        // Step 1: check sessions exist — simple count, no JOIN
+        var sessionCount = await db.ExamSessions
+            .CountAsync(x => x.ExamPlanId == job.PlanId, ct);
+        if (sessionCount == 0)
+            throw new ExamPublishValidationException(
+                "至少安排一个考试场次后才能发布。");
+
+        // Step 2: load session summaries — only necessary columns, no Include chains
+        var sessions = await db.ExamSessions
+            .AsNoTracking()
+            .Where(x => x.ExamPlanId == job.PlanId)
+            .Select(x => new
+            {
+                x.Id,
+                x.TeachingTaskId,
+                x.ClassroomId,
+                InvigilatorCount = x.Invigilators.Count,
+                RoomLinkCount = x.RoomLinks.Count
+            })
+            .ToListAsync(ct);
+
+        // Step 3: load roster counts — independent query
+        var taskIds = sessions.Select(x => x.TeachingTaskId).ToArray();
+        var rosterCounts = (await TeachingTaskRosterQuery
+                .LoadForTasksAsync(db, taskIds, ct))
+            .GroupBy(x => x.TeachingTaskId)
+            .ToDictionary(x => x.Key, x => x.Count());
+
+        // Step 4: validate each session's assignment completeness
+        var unassignedSessionIds = new List<Guid>();
+        foreach (var session in sessions)
+        {
+            var rosterCount = rosterCounts.GetValueOrDefault(session.TeachingTaskId);
+            if (session.RoomLinkCount > 0)
+            {
+                // Has room links — check seat assignment via separate query
+                var assignedSeatCount = await db.ExamSeats
+                    .CountAsync(seat =>
+                            seat.ExamSessionId == session.Id,
+                        ct);
+                if (assignedSeatCount != rosterCount)
+                    unassignedSessionIds.Add(session.Id);
+            }
+            else if (!session.ClassroomId.HasValue ||
+                     session.InvigilatorCount == 0)
+            {
+                unassignedSessionIds.Add(session.Id);
+            }
+        }
+
+        if (unassignedSessionIds.Count > 0)
+            throw new ExamPublishValidationException(
+                $"还有 {unassignedSessionIds.Count} 个教学班未完成考场座位或监考安排，" +
+                "请先完成自动编排。");
+
+        // Step 5: check room invigilator sufficiency — separate query
+        var insufficientInvigilatorCount = await db.ExamRoomSessions
+            .Where(link =>
+                link.ExamRoom!.ExamPlanId == job.PlanId &&
+                link.ExamRoom.Invigilators.Count <
+                link.ExamRoom.RequiredInvigilatorCount)
+            .Select(link => link.ExamSessionId)
+            .Distinct()
+            .CountAsync(ct);
+        if (insufficientInvigilatorCount > 0)
+            throw new ExamPublishValidationException(
+                $"还有 {insufficientInvigilatorCount} 个场次的混排考场监考教师不足，" +
+                "请先完成自动编排。");
+
+        // Step 6: validate mixed rooms — split into two independent queries
+        //   to avoid Seats × SessionLinks Cartesian product
+
+        // 6a: capacity overflow
+        var overCapacityCount = await db.ExamRooms
+            .Where(r => r.ExamPlanId == job.PlanId)
+            .Select(r => new
+            {
+                r.Id,
+                SeatCount = r.Seats.Count,
+                Capacity = r.Classroom!.Capacity
+            })
+            .CountAsync(x => x.SeatCount > x.Capacity, ct);
+        if (overCapacityCount > 0)
+            throw new ExamPublishValidationException(
+                $"发现 {overCapacityCount} 个考场容量超限，请重新编排。");
+
+        // 6b: course mismatch
+        var courseMismatchCount = await db.ExamRoomSessions
+            .Where(link =>
+                link.ExamRoom!.ExamPlanId == job.PlanId &&
+                link.ExamSession!.TeachingTask!.CourseId !=
+                link.ExamRoom.CourseId)
+            .Select(link => link.ExamRoomId)
+            .Distinct()
+            .CountAsync(ct);
+        if (courseMismatchCount > 0)
+            throw new ExamPublishValidationException(
+                $"发现 {courseMismatchCount} 个考场混入不同课程，请重新编排。");
+
+        // Step 7: publish
+        plan.Status = ExamPlanStatus.Published;
+        plan.PublishedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(ct);
+    }
+
+    private async Task PublishMakeupExamAsync(
+        ExamPublishJob job,
+        CancellationToken ct)
+    {
+        var plan = await db.MakeupExamPlans
+            .FirstOrDefaultAsync(x => x.Id == job.PlanId, ct);
+        if (plan is null)
+            throw new ExamPublishValidationException("补考计划不存在。");
+        if (plan.Status != MakeupExamPlanStatus.Draft)
+            throw new ExamPublishValidationException("只有草稿补考计划可以发布。");
+
+        // Step 1: check sessions exist — simple count
+        var sessionCount = await db.MakeupExamSessions
+            .CountAsync(x => x.MakeupExamPlanId == job.PlanId, ct);
+        if (sessionCount == 0)
+            throw new ExamPublishValidationException(
+                "至少安排一个考试场次后才能发布。");
+
+        // Step 2: load session summaries — only necessary columns
+        var sessions = await db.MakeupExamSessions
+            .AsNoTracking()
+            .Where(x => x.MakeupExamPlanId == job.PlanId)
+            .Select(x => new
+            {
+                x.Id,
+                x.ClassroomId,
+                InvigilatorCount = x.Invigilators.Count,
+                EnrollmentCount = x.Enrollments.Count
+            })
+            .ToListAsync(ct);
+
+        // Step 3: validate completeness — no Include chain needed
+        var unassigned = sessions.Count(x =>
+            !x.ClassroomId.HasValue || x.InvigilatorCount == 0);
+        if (unassigned > 0)
+            throw new ExamPublishValidationException(
+                $"还有 {unassigned} 个场次未分配考场或监考教师，请先完成自动编排。");
+
+        // Step 4: validate enrollments
+        var empty = sessions.Count(x => x.EnrollmentCount == 0);
+        if (empty > 0)
+            throw new ExamPublishValidationException(
+                $"还有 {empty} 个场次没有登记补考学生。");
+
+        // Step 5: publish
+        plan.Status = MakeupExamPlanStatus.Published;
+        plan.PublishedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(ct);
+    }
+
+    private async Task MarkFailedAsync(Guid jobId, string message)
+    {
+        db.ChangeTracker.Clear();
+        var job = await db.ExamPublishJobs.FirstOrDefaultAsync(
+            x => x.Id == jobId,
+            CancellationToken.None);
+        if (job is null)
+            return;
+
+        job.Status = ExamPublishJobStatus.Failed;
+        job.ActivePlanId = null;
+        job.CurrentStep = "发布失败";
+        job.ErrorMessage = message.Length <= 2000 ? message : message[..2000];
+        job.CompletedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(CancellationToken.None);
+    }
+}
+
+public sealed class ExamPublishValidationException(string message)
+    : InvalidOperationException(message);

src/Jiaowu.Api/Infrastructure/Exams/ExamSignInExportJobProcessor.cs

@@ -0,0 +1,212 @@
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Jiaowu.Api.Infrastructure.Teaching;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.Exams;
+
+public sealed class ExamSignInExportJobProcessor(
+    AppDbContext db,
+    ILogger<ExamSignInExportJobProcessor> logger)
+{
+    public async Task ProcessAsync(Guid jobId, CancellationToken stoppingToken)
+    {
+        try
+        {
+            var job = await db.ExamSignInExportJobs
+                .FirstOrDefaultAsync(x => x.Id == jobId, stoppingToken);
+            if (job is null ||
+                job.Status is ExamSignInExportJobStatus.Succeeded
+                    or ExamSignInExportJobStatus.Failed)
+            {
+                return;
+            }
+
+            job.Status = ExamSignInExportJobStatus.Running;
+            job.StartedAt ??= DateTime.UtcNow;
+            job.CompletedAt = null;
+            job.ErrorMessage = null;
+            job.CurrentStep = "正在生成考场签名单";
+            await db.SaveChangesAsync(stoppingToken);
+
+            var plan = await db.ExamPlans.AsNoTracking()
+                .Where(x => x.Id == job.PlanId)
+                .Select(x => new
+                {
+                    x.Name,
+                    TermName = x.AcademicTerm!.Name
+                })
+                .FirstOrDefaultAsync(stoppingToken);
+            if (plan is null)
+            {
+                await MarkFailedAsync(jobId, "考试计划不存在。");
+                return;
+            }
+
+            var rooms = await db.ExamRooms.AsNoTracking()
+                .Include(x => x.Course)
+                .Include(x => x.Classroom)
+                    .ThenInclude(x => x!.Building)
+                .Include(x => x.Invigilators)
+                    .ThenInclude(x => x.Teacher)
+                .Include(x => x.SessionLinks)
+                    .ThenInclude(x => x.ExamSession)
+                        .ThenInclude(x => x!.TeachingTask)
+                .Include(x => x.Seats)
+                    .ThenInclude(x => x.Student)
+                        .ThenInclude(x => x!.AdministrativeClass)
+                .Where(x => x.ExamPlanId == job.PlanId)
+                .OrderBy(x => x.ExamDate)
+                .ThenBy(x => x.StartPeriod)
+                .ThenBy(x => x.Classroom!.Building!.Name)
+                .ThenBy(x => x.Classroom!.Name)
+                .AsSplitQuery()
+                .ToListAsync(stoppingToken);
+
+            var legacySessions = await db.ExamSessions.AsNoTracking()
+                .Where(x => x.ExamPlanId == job.PlanId)
+                .Where(x => !x.RoomLinks.Any())
+                .OrderBy(x => x.ExamDate)
+                .ThenBy(x => x.StartPeriod)
+                .Select(session => new
+                {
+                    session.Id,
+                    session.TeachingTaskId,
+                    session.ExamDate,
+                    session.StartsAt,
+                    session.EndsAt,
+                    CourseCode = session.TeachingTask!.Course!.Code,
+                    CourseName = session.TeachingTask.Course.Name,
+                    session.TeachingTask.TaskNumber,
+                    BuildingName = session.Classroom != null
+                        ? session.Classroom.Building!.Name
+                        : null,
+                    ClassroomName = session.Classroom != null
+                        ? session.Classroom.Name
+                        : null,
+                    InvigilatorNames = session.Invigilators
+                        .OrderBy(item => item.Teacher!.TeacherNumber)
+                        .Select(item => item.Teacher!.Name)
+                })
+                .ToListAsync(stoppingToken);
+
+            if (rooms.Count == 0 && legacySessions.Count == 0)
+            {
+                await MarkFailedAsync(jobId, "当前考试计划没有可导出的考试场次。");
+                return;
+            }
+
+            var roster = await TeachingTaskRosterQuery.LoadForTasksAsync(
+                db,
+                legacySessions.Select(x => x.TeachingTaskId),
+                stoppingToken);
+            var studentsByTask = roster.ToLookup(x => x.TeachingTaskId);
+
+            var sheets = rooms.Select(room => new ExamSignInSessionData(
+                    room.Id,
+                    room.ExamDate,
+                    room.StartsAt,
+                    room.EndsAt,
+                    room.Course!.Code,
+                    room.Course.Name,
+                    string.Join(
+                        "、",
+                        room.SessionLinks
+                            .Select(link =>
+                                link.ExamSession!.TeachingTask!.TaskNumber)
+                            .Distinct()
+                            .OrderBy(x => x)),
+                    room.Classroom!.Building!.Name,
+                    room.Classroom.Name,
+                    room.Invigilators
+                        .OrderBy(item => item.Teacher!.TeacherNumber)
+                        .Select(item => item.Teacher!.Name)
+                        .ToList(),
+                    room.Seats
+                        .OrderBy(seat => seat.SeatNumber)
+                        .Select(seat => new ExamSignInStudentData(
+                            seat.StudentId,
+                            seat.Student!.StudentNumber,
+                            seat.Student.Name,
+                            seat.Student.AdministrativeClass!.Name,
+                            seat.SeatNumber))
+                        .ToList()))
+                .Concat(legacySessions.Select(session =>
+                    new ExamSignInSessionData(
+                        session.Id,
+                        session.ExamDate,
+                        session.StartsAt,
+                        session.EndsAt,
+                        session.CourseCode,
+                        session.CourseName,
+                        session.TaskNumber,
+                        session.BuildingName,
+                        session.ClassroomName,
+                        session.InvigilatorNames.ToList(),
+                        studentsByTask[session.TeachingTaskId]
+                            .Select((student, index) =>
+                                new ExamSignInStudentData(
+                                    student.StudentId,
+                                    student.StudentNumber,
+                                    student.Name,
+                                    student.ClassName,
+                                    index + 1))
+                            .ToList())))
+                .ToList();
+
+            var data = new ExamSignInWorkbookData(plan.Name, plan.TermName, sheets);
+            var bytes = ExamSignInWorkbookExporter.Create(data);
+
+            job.Status = ExamSignInExportJobStatus.Succeeded;
+            job.FileName = $"考场签名单-{SanitizeFileName(plan.Name)}.xlsx";
+            job.FileBytes = bytes;
+            job.FileSize = bytes.Length;
+            job.CurrentStep = "生成完成";
+            job.CompletedAt = DateTime.UtcNow;
+            await db.SaveChangesAsync(stoppingToken);
+
+            logger.LogInformation(
+                "Sign-in export job {JobId} for plan {PlanId} completed, {Size:N0} bytes.",
+                job.Id,
+                job.PlanId,
+                bytes.Length);
+        }
+        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
+        {
+            logger.LogInformation(
+                "Sign-in export job {JobId} was interrupted by application shutdown.",
+                jobId);
+            throw;
+        }
+        catch (Exception exception)
+        {
+            logger.LogError(exception, "Sign-in export job {JobId} failed.", jobId);
+            await MarkFailedAsync(jobId, exception.GetBaseException().Message);
+        }
+    }
+
+    private async Task MarkFailedAsync(Guid jobId, string message)
+    {
+        db.ChangeTracker.Clear();
+        var job = await db.ExamSignInExportJobs.FirstOrDefaultAsync(
+            x => x.Id == jobId,
+            CancellationToken.None);
+        if (job is null)
+            return;
+
+        job.Status = ExamSignInExportJobStatus.Failed;
+        job.CurrentStep = "生成失败";
+        job.ErrorMessage = message.Length <= 2000 ? message : message[..2000];
+        job.CompletedAt = DateTime.UtcNow;
+        await db.SaveChangesAsync(CancellationToken.None);
+    }
+
+    private static string SanitizeFileName(string value)
+    {
+        var invalid = System.IO.Path.GetInvalidFileNameChars().ToHashSet();
+        var normalized = new string(value
+            .Select(c => invalid.Contains(c) ? '_' : c)
+            .ToArray()).Trim();
+        return normalized.Length > 100 ? normalized[..100] : normalized;
+    }
+}

src/Jiaowu.Api/Infrastructure/Exams/ExamSignInWorkbookExporter.cs

@@ -0,0 +1,305 @@
+using ClosedXML.Excel;
+
+namespace Jiaowu.Api.Infrastructure.Exams;
+
+public static class ExamSignInWorkbookExporter
+{
+    private static readonly XLColor Navy = XLColor.FromHtml("#173E72");
+    private static readonly XLColor Teal = XLColor.FromHtml("#24706A");
+    private static readonly XLColor Pale = XLColor.FromHtml("#EFF3F6");
+    private static readonly XLColor Rule = XLColor.FromHtml("#C8D3DA");
+
+    public static byte[] Create(ExamSignInWorkbookData data)
+    {
+        using var workbook = new XLWorkbook();
+        AddSummarySheet(workbook, data);
+
+        var usedNames = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
+        {
+            "考场汇总"
+        };
+        foreach (var session in data.Sessions
+                     .OrderBy(x => x.ExamDate)
+                     .ThenBy(x => x.StartsAt)
+                     .ThenBy(x => x.BuildingName)
+                     .ThenBy(x => x.ClassroomName)
+                     .ThenBy(x => x.CourseCode))
+        {
+            AddSignInSheet(
+                workbook,
+                data,
+                session,
+                UniqueSheetName(session, usedNames));
+        }
+
+        using var stream = new MemoryStream();
+        workbook.SaveAs(stream);
+        return stream.ToArray();
+    }
+
+    private static void AddSummarySheet(
+        XLWorkbook workbook,
+        ExamSignInWorkbookData data)
+    {
+        var sheet = workbook.Worksheets.Add("考场汇总");
+        sheet.Style.Font.FontName = "Microsoft YaHei";
+        sheet.ShowGridLines = false;
+
+        sheet.Range("A1:G1").Merge();
+        sheet.Cell("A1").Value = $"{data.PlanName} · 考场签名单";
+        StyleTitle(sheet.Range("A1:G1"));
+        sheet.Row(1).Height = 34;
+
+        sheet.Range("A2:G2").Merge();
+        sheet.Cell("A2").Value =
+            $"{data.TermName} · 共 {data.Sessions.Count} 个场次 · 导出时间：{DateTime.Now:yyyy-MM-dd HH:mm}";
+        StyleSubTitle(sheet.Range("A2:G2"));
+        sheet.Row(2).Height = 24;
+
+        var headers = new[] { "日期", "时间", "考场", "课程", "教学班", "考生人数", "监考教师" };
+        for (var column = 1; column <= headers.Length; column++)
+            sheet.Cell(4, column).Value = headers[column - 1];
+        StyleHeader(sheet.Range(4, 1, 4, headers.Length));
+
+        var row = 5;
+        foreach (var session in data.Sessions
+                     .OrderBy(x => x.ExamDate)
+                     .ThenBy(x => x.StartsAt)
+                     .ThenBy(x => x.BuildingName)
+                     .ThenBy(x => x.ClassroomName))
+        {
+            sheet.Cell(row, 1).Value = session.ExamDate.ToDateTime(TimeOnly.MinValue);
+            sheet.Cell(row, 1).Style.DateFormat.Format = "yyyy-mm-dd";
+            sheet.Cell(row, 2).Value = $"{session.StartsAt:HH:mm}-{session.EndsAt:HH:mm}";
+            sheet.Cell(row, 3).Value = Location(session);
+            sheet.Cell(row, 4).Value = $"{session.CourseCode} {session.CourseName}";
+            sheet.Cell(row, 5).Value = session.TaskNumber;
+            sheet.Cell(row, 6).Value = session.Students.Count;
+            sheet.Cell(row, 7).Value = Invigilators(session);
+            row++;
+        }
+
+        if (row > 5)
+        {
+            var table = sheet.Range(4, 1, row - 1, headers.Length);
+            table.Style.Border.InsideBorder = XLBorderStyleValues.Thin;
+            table.Style.Border.InsideBorderColor = Rule;
+            table.Style.Border.OutsideBorder = XLBorderStyleValues.Medium;
+            table.Style.Border.OutsideBorderColor = Rule;
+            table.Style.Alignment.Vertical = XLAlignmentVerticalValues.Center;
+            sheet.Rows(5, row - 1).Height = 25;
+        }
+
+        sheet.Column(1).Width = 13;
+        sheet.Column(2).Width = 15;
+        sheet.Column(3).Width = 24;
+        sheet.Column(4).Width = 30;
+        sheet.Column(5).Width = 22;
+        sheet.Column(6).Width = 11;
+        sheet.Column(7).Width = 24;
+        sheet.Columns(3, 7).Style.Alignment.WrapText = true;
+        sheet.SheetView.FreezeRows(4);
+        sheet.PageSetup.PageOrientation = XLPageOrientation.Landscape;
+        sheet.PageSetup.PaperSize = XLPaperSize.A4Paper;
+        sheet.PageSetup.FitToPages(1, 0);
+        sheet.PageSetup.Margins
+            .SetLeft(0.25).SetRight(0.25).SetTop(0.35).SetBottom(0.35);
+    }
+
+    private static void AddSignInSheet(
+        XLWorkbook workbook,
+        ExamSignInWorkbookData data,
+        ExamSignInSessionData session,
+        string sheetName)
+    {
+        var sheet = workbook.Worksheets.Add(sheetName);
+        sheet.Style.Font.FontName = "Microsoft YaHei";
+        sheet.ShowGridLines = false;
+
+        sheet.Range("A1:G1").Merge();
+        sheet.Cell("A1").Value = "考试考场签名单";
+        StyleTitle(sheet.Range("A1:G1"));
+        sheet.Cell("A1").Style.Alignment.Horizontal =
+            XLAlignmentHorizontalValues.Center;
+        sheet.Row(1).Height = 36;
+
+        sheet.Range("A2:G2").Merge();
+        sheet.Cell("A2").Value = $"{data.PlanName} · {data.TermName}";
+        StyleSubTitle(sheet.Range("A2:G2"));
+        sheet.Cell("A2").Style.Alignment.Horizontal =
+            XLAlignmentHorizontalValues.Center;
+        sheet.Row(2).Height = 23;
+
+        sheet.Range("A3:D3").Merge();
+        sheet.Cell("A3").Value =
+            $"课程：{session.CourseCode} {session.CourseName}（{session.TaskNumber}）";
+        sheet.Range("E3:G3").Merge();
+        sheet.Cell("E3").Value = $"考生人数：{session.Students.Count} 人";
+
+        sheet.Range("A4:D4").Merge();
+        sheet.Cell("A4").Value =
+            $"考试时间：{session.ExamDate:yyyy-MM-dd} {session.StartsAt:HH:mm}-{session.EndsAt:HH:mm}";
+        sheet.Range("E4:G4").Merge();
+        sheet.Cell("E4").Value = $"考场：{Location(session)}";
+
+        sheet.Range("A5:D5").Merge();
+        sheet.Cell("A5").Value = $"监考教师：{Invigilators(session)}";
+        sheet.Range("E5:G5").Merge();
+        sheet.Cell("E5").Value = "应到：______  实到：______  缺考：______";
+
+        var metadata = sheet.Range("A3:G5");
+        metadata.Style.Fill.BackgroundColor = XLColor.White;
+        metadata.Style.Font.FontColor = XLColor.FromHtml("#304B60");
+        metadata.Style.Alignment.Vertical = XLAlignmentVerticalValues.Center;
+        metadata.Style.Alignment.WrapText = true;
+        metadata.Style.Border.BottomBorder = XLBorderStyleValues.Thin;
+        metadata.Style.Border.BottomBorderColor = Rule;
+        sheet.Rows(3, 5).Height = 24;
+
+        var headers = new[] { "序号", "座位号", "学号", "姓名", "行政班", "考生签名", "备注" };
+        for (var column = 1; column <= headers.Length; column++)
+            sheet.Cell(7, column).Value = headers[column - 1];
+        StyleHeader(sheet.Range(7, 1, 7, headers.Length));
+        sheet.Row(7).Height = 27;
+
+        var row = 8;
+        foreach (var student in session.Students
+                     .OrderBy(x => x.SeatNumber)
+                     .ThenBy(x => x.StudentNumber))
+        {
+            var index = row - 7;
+            sheet.Cell(row, 1).Value = index;
+            sheet.Cell(row, 2).Value =
+                (student.SeatNumber > 0 ? student.SeatNumber : index)
+                .ToString("D3");
+            sheet.Cell(row, 3).Value = student.StudentNumber;
+            sheet.Cell(row, 4).Value = student.Name;
+            sheet.Cell(row, 5).Value = student.ClassName;
+            sheet.Row(row).Height = 28;
+            row++;
+        }
+
+        if (session.Students.Count == 0)
+        {
+            sheet.Range("A8:G8").Merge();
+            sheet.Cell("A8").Value = "本场次暂无考生";
+            sheet.Cell("A8").Style
+                .Font.SetFontColor(XLColor.FromHtml("#8A5A20"))
+                .Fill.SetBackgroundColor(XLColor.FromHtml("#FFF8EA"))
+                .Alignment.SetHorizontal(XLAlignmentHorizontalValues.Center);
+            sheet.Row(8).Height = 28;
+            row = 9;
+        }
+
+        var roster = sheet.Range(7, 1, row - 1, headers.Length);
+        roster.Style.Border.InsideBorder = XLBorderStyleValues.Thin;
+        roster.Style.Border.InsideBorderColor = Rule;
+        roster.Style.Border.OutsideBorder = XLBorderStyleValues.Medium;
+        roster.Style.Border.OutsideBorderColor = XLColor.FromHtml("#9CADB7");
+        roster.Style.Alignment.Vertical = XLAlignmentVerticalValues.Center;
+        sheet.Range(8, 1, row - 1, 4).Style.Alignment.Horizontal =
+            XLAlignmentHorizontalValues.Center;
+        sheet.Range(8, 5, row - 1, 7).Style.Alignment.WrapText = true;
+
+        sheet.Column(1).Width = 7;
+        sheet.Column(2).Width = 10;
+        sheet.Column(3).Width = 16;
+        sheet.Column(4).Width = 12;
+        sheet.Column(5).Width = 20;
+        sheet.Column(6).Width = 22;
+        sheet.Column(7).Width = 17;
+        sheet.SheetView.FreezeRows(7);
+        sheet.PageSetup.PageOrientation = XLPageOrientation.Portrait;
+        sheet.PageSetup.PaperSize = XLPaperSize.A4Paper;
+        sheet.PageSetup.FitToPages(1, 0);
+        sheet.PageSetup.Margins
+            .SetLeft(0.25).SetRight(0.25).SetTop(0.3).SetBottom(0.3);
+    }
+
+    private static void StyleTitle(IXLRange range) =>
+        range.Style
+            .Font.SetBold()
+            .Font.SetFontSize(18)
+            .Font.SetFontColor(XLColor.White)
+            .Fill.SetBackgroundColor(Navy)
+            .Alignment.SetVertical(XLAlignmentVerticalValues.Center);
+
+    private static void StyleSubTitle(IXLRange range) =>
+        range.Style
+            .Font.SetFontColor(XLColor.FromHtml("#52677A"))
+            .Fill.SetBackgroundColor(Pale)
+            .Alignment.SetVertical(XLAlignmentVerticalValues.Center);
+
+    private static void StyleHeader(IXLRange range) =>
+        range.Style
+            .Font.SetBold()
+            .Font.SetFontColor(XLColor.White)
+            .Fill.SetBackgroundColor(Teal)
+            .Alignment.SetHorizontal(XLAlignmentHorizontalValues.Center)
+            .Alignment.SetVertical(XLAlignmentVerticalValues.Center);
+
+    private static string Location(ExamSignInSessionData session) =>
+        string.Join(" · ", new[]
+        {
+            session.BuildingName,
+            session.ClassroomName
+        }.Where(x => !string.IsNullOrWhiteSpace(x))) is { Length: > 0 } value
+            ? value
+            : "待分配考场";
+
+    private static string Invigilators(ExamSignInSessionData session) =>
+        session.InvigilatorNames.Count > 0
+            ? string.Join('、', session.InvigilatorNames)
+            : "待分配";
+
+    private static string UniqueSheetName(
+        ExamSignInSessionData session,
+        ISet<string> usedNames)
+    {
+        var location = string.IsNullOrWhiteSpace(session.ClassroomName)
+            ? "待分配"
+            : session.ClassroomName;
+        var raw = $"{session.ExamDate:MMdd}-{location}-{session.CourseCode}";
+        var invalidCharacters = new HashSet<char>(":\\/?*[]");
+        var sanitized = new string(raw
+            .Select(character => invalidCharacters.Contains(character) ? '-' : character)
+            .ToArray()).Trim(' ', '\'');
+        if (sanitized.Length == 0) sanitized = "考场";
+        if (sanitized.Length > 31) sanitized = sanitized[..31];
+
+        var candidate = sanitized;
+        var suffix = 2;
+        while (!usedNames.Add(candidate))
+        {
+            var marker = $"-{suffix++}";
+            var prefixLength = Math.Min(sanitized.Length, 31 - marker.Length);
+            candidate = sanitized[..prefixLength] + marker;
+        }
+        return candidate;
+    }
+}
+
+public sealed record ExamSignInWorkbookData(
+    string PlanName,
+    string TermName,
+    IReadOnlyList<ExamSignInSessionData> Sessions);
+
+public sealed record ExamSignInSessionData(
+    Guid SessionId,
+    DateOnly ExamDate,
+    DateTime StartsAt,
+    DateTime EndsAt,
+    string CourseCode,
+    string CourseName,
+    string TaskNumber,
+    string? BuildingName,
+    string? ClassroomName,
+    IReadOnlyList<string> InvigilatorNames,
+    IReadOnlyList<ExamSignInStudentData> Students);
+
+public sealed record ExamSignInStudentData(
+    Guid StudentId,
+    string StudentNumber,
+    string Name,
+    string ClassName,
+    int SeatNumber = 0);

src/Jiaowu.Api/Infrastructure/Exams/InvigilatorCandidateQuery.cs

@@ -0,0 +1,15 @@
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.Exams;
+
+internal static class InvigilatorCandidateQuery
+{
+    public static IQueryable<Teacher> Create(
+        AppDbContext db,
+        IEnumerable<Guid> excludedTeacherIds) =>
+        db.Teachers.AsNoTracking()
+            .Where(x => x.Status == TeacherStatus.Active)
+            .WhereNotIn(excludedTeacherIds, x => x.Id);
+}

src/Jiaowu.Api/Infrastructure/Exams/MakeupExamArrangementService.cs

@@ -11,8 +11,14 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
 
     public async Task<ExamArrangementResult> ArrangeAsync(
         Guid planId,
+        IReadOnlyCollection<Guid>? requestedSessionIds,
+        bool assignClassrooms,
+        bool assignInvigilators,
         CancellationToken cancellationToken)
     {
+        if (!assignClassrooms && !assignInvigilators)
+            return ExamArrangementResult.Fail("请至少选择分配考场或分配监考教师。");
+
         var plan = await db.MakeupExamPlans
             .Include(x => x.AcademicTerm)
             .Include(x => x.Sessions)
@@ -20,6 +26,10 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
             .Include(x => x.Sessions)
                 .ThenInclude(x => x.TeachingTask)
                     .ThenInclude(x => x!.Teachers)
+            .Include(x => x.Sessions)
+                .ThenInclude(x => x.TeachingTask)
+                    .ThenInclude(x => x!.Course)
+            .AsSplitQuery()
             .FirstOrDefaultAsync(x => x.Id == planId, cancellationToken);
 
         if (plan is null)
@@ -27,9 +37,23 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
         if (plan.Status != MakeupExamPlanStatus.Draft)
             return ExamArrangementResult.Fail("只有草稿状态的补考计划可以自动编排。");
 
-        var sessions = plan.Sessions.ToList();
+        var requestedIds = (requestedSessionIds ?? [])
+            .Distinct()
+            .ToHashSet();
+        if (requestedIds.Count > 100)
+            return ExamArrangementResult.Fail("一次最多处理100个补考场次。");
+        if (requestedIds.Count > 0 &&
+            plan.Sessions.Count(x => requestedIds.Contains(x.Id)) != requestedIds.Count)
+            return ExamArrangementResult.Fail("所选场次不存在或不属于当前补考计划。");
+
+        var sessions = plan.Sessions
+            .Where(x => requestedIds.Count == 0 || requestedIds.Contains(x.Id))
+            .OrderBy(x => x.ExamDate)
+            .ThenBy(x => x.StartPeriod)
+            .ThenByDescending(x => x.RequiredInvigilatorCount)
+            .ToList();
         if (sessions.Count == 0)
-            return ExamArrangementResult.Fail("补考计划中没有场次。");
+            return ExamArrangementResult.Fail("没有可处理的补考场次。");
 
         var termId = plan.AcademicTermId;
         var timeSlots = await db.ScheduleTimeSlots.AsNoTracking()
@@ -44,8 +68,8 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
 
         int assignedRooms = 0;
         int assignedInvigilators = 0;
-        int skippedRooms = 0;
+        int unavailableRooms = 0;
-        int skippedInvigilators = 0;
+        int unavailableInvigilators = 0;
         var messages = new List<string>();
 
         var occupiedRooms = sessions
@@ -66,7 +90,7 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
                 .CountAsync(x => x.MakeupExamSessionId == session.Id, cancellationToken);
 
             // Auto-assign classroom
-            if (!session.ClassroomId.HasValue)
+            if (assignClassrooms && !session.ClassroomId.HasValue)
             {
                 var room = await FindBestClassroomAsync(
                     session, enrolledCount, occupiedRooms, cancellationToken);
@@ -76,24 +100,19 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
                     occupiedRooms.Add(new RoomOccupancy(room.Id, session.StartsAt, session.EndsAt));
                     assignedRooms++;
                     messages.Add(
-                        $"\"{session.TeachingTask!.Course!.Name}\"→{room.Name}({room.Capacity}座)");
+                        $"\"{session.TeachingTask!.Course!.Name}\"→{room.Name}({room.Capacity / 2}座)");
                 }
                 else
                 {
-                    skippedRooms++;
+                    unavailableRooms++;
                     messages.Add(
                         $"\"{session.TeachingTask!.Course!.Name}\"：无可用考场（需≥{enrolledCount}座）");
                 }
             }
-            else
-            {
-                skippedRooms++;
-            }
-
             // Auto-assign invigilators
             var currentInvigilatorCount = session.Invigilators.Count;
             var needed = session.RequiredInvigilatorCount - currentInvigilatorCount;
-            if (needed > 0)
+            if (assignInvigilators && needed > 0)
             {
                 var courseTeacherIds = session.TeachingTask!.Teachers
                     .Select(x => x.TeacherId).ToHashSet();
@@ -113,12 +132,11 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
                 }
 
                 if (newlyAssigned.Count < needed)
+                {
+                    unavailableInvigilators += needed - newlyAssigned.Count;
                     messages.Add(
                         $"\"{session.TeachingTask!.Course!.Name}\"：仅找到{newlyAssigned.Count}/{needed}名监考教师");
                 }
-            else
-            {
-                skippedInvigilators++;
             }
         }
 
@@ -126,8 +144,9 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
 
         return new ExamArrangementResult(
             true,
-            $"{assignedRooms}个考场、{assignedInvigilators}名监考已分配。" +
+            $"{sessions.Count}个场次处理完成，分配{assignedRooms}个考场、{assignedInvigilators}名监考教师。" +
-            (skippedRooms > 0 ? $" {skippedRooms}个场次无可用考场。" : "") +
+            (unavailableRooms > 0 ? $" {unavailableRooms}个场次暂无可用考场。" : "") +
+            (unavailableInvigilators > 0 ? $" 仍缺{unavailableInvigilators}名监考教师。" : "") +
             (messages.Count > 0 ? $" 详情：{string.Join("；", messages.Take(10))}" : ""));
     }
 
@@ -152,10 +171,13 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
         CancellationToken cancellationToken)
     {
         var query = db.Classrooms.AsNoTracking()
-            .Where(x => x.IsEnabled && x.Capacity >= enrolledCount);
+            .Where(x => x.IsEnabled && x.Capacity >= enrolledCount * 2);
 
+        var buildingIds = ParseBuildingIds(session.RequiredBuildingIds);
         if (session.RequiredBuildingId.HasValue)
-            query = query.Where(x => x.BuildingId == session.RequiredBuildingId.Value);
+            buildingIds.Add(session.RequiredBuildingId.Value);
+        if (buildingIds.Count > 0)
+            query = query.Where(x => buildingIds.Contains(x.BuildingId));
 
         var occupiedRoomIds = occupied
             .Where(x => ExamConflictRules.TimeOverlaps(
@@ -207,11 +229,27 @@ public sealed class MakeupExamArrangementService(AppDbContext db)
         foreach (var id in dbBusyIds) busyTeacherIds.Add(id);
         foreach (var id in excludeTeacherIds) busyTeacherIds.Add(id);
 
-        return await db.Teachers.AsNoTracking()
+        var candidates = await InvigilatorCandidateQuery
-            .Where(x => x.Status == TeacherStatus.Active)
+            .Create(db, busyTeacherIds)
-            .WhereNotIn(busyTeacherIds, x => x.Id)
-            .OrderBy(x => Guid.NewGuid())
-            .Take(needed)
             .ToListAsync(cancellationToken);
+
+        return candidates
+            .OrderBy(_ => Random.Shared.Next())
+            .Take(needed)
+            .ToList();
+    }
+
+    private static HashSet<Guid> ParseBuildingIds(string? json)
+    {
+        if (string.IsNullOrWhiteSpace(json))
+            return [];
+        try
+        {
+            return System.Text.Json.JsonSerializer.Deserialize<HashSet<Guid>>(json) ?? [];
+        }
+        catch
+        {
+            return [];
+        }
     }
 }

src/Jiaowu.Api/Infrastructure/Exams/MakeupExamAutoJobs.cs

@@ -1,111 +1,10 @@
 using System.Text.Json;
-using System.Threading.Channels;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.EntityFrameworkCore;
 
 namespace Jiaowu.Api.Infrastructure.Exams;
 
-public sealed class MakeupExamAutoJobQueue
-{
-    private readonly Channel<Guid> _channel = Channel.CreateUnbounded<Guid>(
-        new UnboundedChannelOptions
-        {
-            SingleReader = true,
-            SingleWriter = false
-        });
-
-    public void Enqueue(Guid jobId)
-    {
-        if (!_channel.Writer.TryWrite(jobId))
-            throw new InvalidOperationException("补考自动生成任务队列当前不可用。");
-    }
-
-    public IAsyncEnumerable<Guid> ReadAllAsync(CancellationToken cancellationToken) =>
-        _channel.Reader.ReadAllAsync(cancellationToken);
-}
-
-public sealed class MakeupExamAutoJobWorker(
-    IServiceScopeFactory scopeFactory,
-    MakeupExamAutoJobQueue queue,
-    ILogger<MakeupExamAutoJobWorker> logger) : BackgroundService
-{
-    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
-    {
-        try
-        {
-            await RecoverInterruptedJobsAsync(stoppingToken);
-        }
-        catch (Exception exception)
-        {
-            logger.LogWarning(
-                exception,
-                "Could not recover makeup exam auto jobs (table may not exist yet).");
-        }
-
-        try
-        {
-            await foreach (var jobId in queue.ReadAllAsync(stoppingToken))
-            {
-                try
-                {
-                    await using var scope = scopeFactory.CreateAsyncScope();
-                    var processor = scope.ServiceProvider
-                        .GetRequiredService<MakeupExamAutoJobProcessor>();
-                    await processor.ProcessAsync(jobId, stoppingToken);
-                }
-                catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
-                {
-                    throw;
-                }
-                catch (Exception exception)
-                {
-                    logger.LogError(
-                        exception,
-                        "Unexpected failure while dispatching makeup exam auto job {JobId}.",
-                        jobId);
-                }
-            }
-        }
-        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
-        {
-            logger.LogInformation("Makeup exam auto job worker is stopping.");
-        }
-    }
-
-    private async Task RecoverInterruptedJobsAsync(CancellationToken cancellationToken)
-    {
-        await using var scope = scopeFactory.CreateAsyncScope();
-        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
-        var jobs = await db.MakeupExamAutoJobs
-            .Where(x =>
-                x.Status == MakeupExamAutoJobStatus.Queued ||
-                x.Status == MakeupExamAutoJobStatus.Running)
-            .OrderBy(x => x.CreatedAt)
-            .ToListAsync(cancellationToken);
-
-        foreach (var job in jobs)
-        {
-            job.Status = MakeupExamAutoJobStatus.Queued;
-            job.StartedAt = null;
-            job.CompletedAt = null;
-            job.ErrorMessage = null;
-        }
-
-        if (jobs.Count > 0)
-            await db.SaveChangesAsync(cancellationToken);
-        foreach (var job in jobs)
-            queue.Enqueue(job.Id);
-
-        if (jobs.Count > 0)
-        {
-            logger.LogInformation(
-                "Recovered {JobCount} queued or interrupted makeup exam auto jobs.",
-                jobs.Count);
-        }
-    }
-}
-
 public sealed class MakeupExamAutoJobProcessor(
     AppDbContext db,
     MakeupExamEligibilityService eligibilityService,

src/Jiaowu.Api/Infrastructure/Experiments/CentralizedExperimentConflictQuery.cs

@@ -0,0 +1,59 @@
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.Experiments;
+
+internal static class CentralizedExperimentConflictQuery
+{
+    public static IQueryable<Guid> TaskIdsForTeachers(
+        AppDbContext db,
+        IReadOnlyCollection<Guid> teacherIds) =>
+        db.TeachingTaskTeachers.AsNoTracking()
+            .WhereIn(teacherIds, x => x.TeacherId)
+            .Select(x => x.TeachingTaskId);
+
+    public static IQueryable<Guid> TaskIdsForClasses(
+        AppDbContext db,
+        IReadOnlyCollection<Guid> classIds) =>
+        db.TeachingTaskClasses.AsNoTracking()
+            .WhereIn(classIds, x => x.AdministrativeClassId)
+            .Select(x => x.TeachingTaskId);
+
+    public static IQueryable<ScheduleEntry> ScheduleEntries(
+        AppDbContext db,
+        IReadOnlyCollection<Guid> relatedTaskIds,
+        Guid academicTermId,
+        int dayOfWeek,
+        int week,
+        int startPeriod,
+        int periodCount) =>
+        db.ScheduleEntries.AsNoTracking()
+            .Where(x =>
+                x.SchedulePlan!.Status == SchedulePlanStatus.Published &&
+                x.SchedulePlan.AcademicTermId == academicTermId &&
+                x.DayOfWeek == dayOfWeek &&
+                x.StartWeek <= week &&
+                x.EndWeek >= week &&
+                x.StartPeriod < startPeriod + periodCount &&
+                startPeriod < x.StartPeriod + x.PeriodCount)
+            .WhereIn(relatedTaskIds, x => x.TeachingTaskId);
+
+    public static IQueryable<ExperimentSession> ExperimentSessions(
+        AppDbContext db,
+        IReadOnlyCollection<Guid> relatedTaskIds,
+        DateOnly date,
+        int startPeriod,
+        int periodCount) =>
+        db.ExperimentSessions.AsNoTracking()
+            .Where(x =>
+                x.Status == ExperimentSessionStatus.Scheduled &&
+                x.SessionDate == date &&
+                x.StartPeriod < startPeriod + periodCount &&
+                startPeriod < x.StartPeriod + x.PeriodCount &&
+                x.ExperimentProject!.ArrangementMode ==
+                    ExperimentArrangementMode.Centralized)
+            .WhereIn(
+                relatedTaskIds,
+                x => x.ExperimentProject!.TeachingTaskId);
+}

src/Jiaowu.Api/Infrastructure/Grades/ExperimentGradeAggregationService.cs

@@ -0,0 +1,88 @@
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.Grades;
+
+public static class ExperimentGradeAggregationService
+{
+    public static async Task<ExperimentGradeAggregateResult> CalculateAsync(
+        AppDbContext db,
+        Guid teachingTaskId,
+        IReadOnlyCollection<Guid> studentIds,
+        CancellationToken cancellationToken)
+    {
+        var sheets = await db.ExperimentGradeSheets.AsNoTracking()
+            .Where(x =>
+                x.Status ==
+                    Domain.Academic.ExperimentGradeSheetStatus.Published &&
+                x.ExperimentProject!.TeachingTaskId == teachingTaskId)
+            .OrderBy(x => x.ExperimentProject!.Code)
+            .Select(x => new PublishedExperimentSheet(
+                x.Id,
+                x.ExperimentProject!.Code,
+                x.ExperimentProject.Name,
+                x.ContributionWeight,
+                x.Records.Select(record => new PublishedExperimentScore(
+                    record.StudentId,
+                    record.TotalScore)).ToList()))
+            .AsSplitQuery()
+            .ToListAsync(cancellationToken);
+
+        var scores = new Dictionary<Guid, decimal?>();
+        foreach (var studentId in studentIds.Distinct())
+        {
+            decimal weightedTotal = 0;
+            decimal totalWeight = 0;
+            var complete = sheets.Count > 0;
+            foreach (var sheet in sheets)
+            {
+                var score = sheet.Scores.FirstOrDefault(x =>
+                    x.StudentId == studentId);
+                if (score?.TotalScore is not decimal totalScore)
+                {
+                    complete = false;
+                    break;
+                }
+                weightedTotal += totalScore * sheet.ContributionWeight;
+                totalWeight += sheet.ContributionWeight;
+            }
+            scores[studentId] = complete && totalWeight > 0
+                ? Math.Round(
+                    weightedTotal / totalWeight,
+                    1,
+                    MidpointRounding.AwayFromZero)
+                : null;
+        }
+
+        return new ExperimentGradeAggregateResult(
+            sheets.Count,
+            sheets.Select(x => new ExperimentGradeAggregateProject(
+                x.Id,
+                x.Code,
+                x.Name,
+                x.ContributionWeight)).ToList(),
+            scores);
+    }
+
+    private sealed record PublishedExperimentSheet(
+        Guid Id,
+        string Code,
+        string Name,
+        decimal ContributionWeight,
+        List<PublishedExperimentScore> Scores);
+
+    private sealed record PublishedExperimentScore(
+        Guid StudentId,
+        decimal? TotalScore);
+}
+
+public sealed record ExperimentGradeAggregateResult(
+    int PublishedProjectCount,
+    IReadOnlyList<ExperimentGradeAggregateProject> Projects,
+    IReadOnlyDictionary<Guid, decimal?> Scores);
+
+public sealed record ExperimentGradeAggregateProject(
+    Guid Id,
+    string Code,
+    string Name,
+    decimal ContributionWeight);

src/Jiaowu.Api/Infrastructure/Grades/ExperimentGradeCalculator.cs

@@ -0,0 +1,45 @@
+using Jiaowu.Api.Domain.Academic;
+
+namespace Jiaowu.Api.Infrastructure.Grades;
+
+public static class ExperimentGradeCalculator
+{
+    public static bool AreWeightsValid(
+        decimal contributionWeight,
+        decimal passScore,
+        IEnumerable<ExperimentGradeItem> items)
+    {
+        var itemList = items.ToList();
+        return contributionWeight is > 0 and <= 100 &&
+               passScore is >= 0 and <= 100 &&
+               itemList.Count > 0 &&
+               itemList.All(item => item.Weight is > 0 and <= 100) &&
+               itemList.Sum(item => item.Weight) == 100;
+    }
+
+    public static decimal? CalculateTotal(
+        ExperimentGradeRecord record,
+        IReadOnlyCollection<ExperimentGradeItem> items)
+    {
+        if (record.SafetyViolation ||
+            record.ParticipationStatus == ExperimentParticipationStatus.Absent)
+            return 0;
+        if (record.ParticipationStatus is
+            ExperimentParticipationStatus.Pending or
+            ExperimentParticipationStatus.Excused or
+            ExperimentParticipationStatus.Exempt)
+            return null;
+
+        var scores = record.ItemScores.ToDictionary(
+            x => x.ExperimentGradeItemId);
+        decimal total = 0;
+        foreach (var item in items)
+        {
+            if (!scores.TryGetValue(item.Id, out var score) ||
+                !score.Score.HasValue)
+                return null;
+            total += score.Score.Value * item.Weight / 100;
+        }
+        return Math.Round(total, 1, MidpointRounding.AwayFromZero);
+    }
+}

src/Jiaowu.Api/Infrastructure/Graduation/AcademicPlanningRules.cs

@@ -0,0 +1,115 @@
+using Jiaowu.Api.Domain.Academic;
+
+namespace Jiaowu.Api.Infrastructure.Graduation;
+
+public sealed record AcademicPlanningCourseSnapshot(
+    Guid CourseId,
+    string CourseName,
+    decimal Credits,
+    int RecommendedSemester,
+    CurriculumCourseType Type,
+    IReadOnlyCollection<Guid> PrerequisiteCourseIds);
+
+public sealed record AcademicPlanningPrerequisiteIssue(
+    Guid CourseId,
+    Guid PrerequisiteCourseId,
+    int PlannedSemester,
+    int? PrerequisitePlannedSemester);
+
+public static class AcademicPlanningRules
+{
+    public const decimal RecommendedSemesterCreditLimit = 24;
+    public const decimal HeavySemesterCreditLimit = 30;
+
+    public static IReadOnlyList<AcademicPlanningPrerequisiteIssue>
+        FindPrerequisiteIssues(
+            IEnumerable<AcademicPlanningCourseSnapshot> courses,
+            IReadOnlySet<Guid> completedCourseIds,
+            IReadOnlySet<Guid> inProgressCourseIds,
+            IReadOnlyDictionary<Guid, int> plannedSemesters)
+    {
+        var issues = new List<AcademicPlanningPrerequisiteIssue>();
+        foreach (var course in courses.Where(x =>
+                     plannedSemesters.ContainsKey(x.CourseId)))
+        {
+            var plannedSemester = plannedSemesters[course.CourseId];
+            foreach (var prerequisiteId in course.PrerequisiteCourseIds)
+            {
+                if (completedCourseIds.Contains(prerequisiteId) ||
+                    inProgressCourseIds.Contains(prerequisiteId))
+                    continue;
+
+                if (!plannedSemesters.TryGetValue(
+                        prerequisiteId,
+                        out var prerequisiteSemester) ||
+                    prerequisiteSemester >= plannedSemester)
+                {
+                    issues.Add(new AcademicPlanningPrerequisiteIssue(
+                        course.CourseId,
+                        prerequisiteId,
+                        plannedSemester,
+                        plannedSemesters.GetValueOrDefault(prerequisiteId)));
+                }
+            }
+        }
+        return issues;
+    }
+
+    public static IReadOnlyList<Guid> SuggestNextSemester(
+        IEnumerable<AcademicPlanningCourseSnapshot> courses,
+        IReadOnlySet<Guid> completedCourseIds,
+        IReadOnlySet<Guid> inProgressCourseIds,
+        int nextSemester,
+        decimal targetCredits = RecommendedSemesterCreditLimit)
+    {
+        var available = courses
+            .Where(x =>
+                !completedCourseIds.Contains(x.CourseId) &&
+                !inProgressCourseIds.Contains(x.CourseId) &&
+                x.RecommendedSemester <= nextSemester &&
+                x.PrerequisiteCourseIds.All(prerequisiteId =>
+                    completedCourseIds.Contains(prerequisiteId) ||
+                    inProgressCourseIds.Contains(prerequisiteId)))
+            .OrderBy(x => x.Type == CurriculumCourseType.Required ? 0 : 1)
+            .ThenBy(x => x.RecommendedSemester > nextSemester ? 1 : 0)
+            .ThenBy(x => x.RecommendedSemester)
+            .ThenBy(x => x.CourseName)
+            .ToList();
+
+        var selected = new List<Guid>();
+        decimal credits = 0;
+        foreach (var course in available)
+        {
+            var isOverdueRequired =
+                course.Type == CurriculumCourseType.Required &&
+                course.RecommendedSemester <= nextSemester;
+            if (!isOverdueRequired &&
+                selected.Count > 0 &&
+                credits + course.Credits > targetCredits)
+                continue;
+
+            selected.Add(course.CourseId);
+            credits += course.Credits;
+            if (credits >= targetCredits) break;
+        }
+        return selected;
+    }
+
+    public static int EstimateCompletionSemester(
+        int nextSemester,
+        int latestPlannedSemester,
+        decimal remainingCredits,
+        int remainingRequirementCount)
+    {
+        if (remainingCredits <= 0 && remainingRequirementCount <= 0)
+            return Math.Max(nextSemester - 1, latestPlannedSemester);
+
+        var byCredits = (int)Math.Ceiling(
+            Math.Max(remainingCredits, 0) / RecommendedSemesterCreditLimit);
+        var byRequirements = (int)Math.Ceiling(
+            Math.Max(remainingRequirementCount, 0) / 6m);
+        var additionalSemesters = Math.Max(1, Math.Max(byCredits, byRequirements));
+        return Math.Max(nextSemester - 1, latestPlannedSemester) +
+               additionalSemesters;
+    }
+}

src/Jiaowu.Api/Infrastructure/Observability/DatabaseCommandTelemetryInterceptor.cs

@@ -0,0 +1,281 @@
+using System.Data.Common;
+using System.Diagnostics;
+using System.Diagnostics.Metrics;
+using System.Security.Cryptography;
+using System.Text;
+using Microsoft.EntityFrameworkCore.Diagnostics;
+
+namespace Jiaowu.Api.Infrastructure.Observability;
+
+public sealed class DatabaseCommandTelemetryInterceptor(
+    ObservabilityOptions options,
+    ILogger<DatabaseCommandTelemetryInterceptor> logger)
+    : DbCommandInterceptor
+{
+    public const string ActivitySourceName = "Jiaowu.Api.Database";
+    public const string MeterName = "Jiaowu.Api.Database";
+
+    private static readonly ActivitySource ActivitySource =
+        new(ActivitySourceName);
+    private static readonly Meter Meter = new(MeterName);
+    private static readonly Histogram<double> CommandDuration =
+        Meter.CreateHistogram<double>(
+            "jiaowu.db.command.duration",
+            "ms",
+            "EF Core database command duration");
+    private static readonly Counter<long> SlowCommandCount =
+        Meter.CreateCounter<long>(
+            "jiaowu.db.command.slow",
+            "{command}",
+            "EF Core commands exceeding the configured slow-query threshold");
+    private static readonly Counter<long> FailedCommandCount =
+        Meter.CreateCounter<long>(
+            "jiaowu.db.command.failed",
+            "{command}",
+            "Failed EF Core database commands");
+
+    public override DbDataReader ReaderExecuted(
+        DbCommand command,
+        CommandExecutedEventData eventData,
+        DbDataReader result)
+    {
+        Observe(command, eventData.Duration, "reader");
+        return result;
+    }
+
+    public override ValueTask<DbDataReader> ReaderExecutedAsync(
+        DbCommand command,
+        CommandExecutedEventData eventData,
+        DbDataReader result,
+        CancellationToken cancellationToken = default)
+    {
+        Observe(command, eventData.Duration, "reader");
+        return ValueTask.FromResult(result);
+    }
+
+    public override int NonQueryExecuted(
+        DbCommand command,
+        CommandExecutedEventData eventData,
+        int result)
+    {
+        Observe(command, eventData.Duration, "nonquery");
+        return result;
+    }
+
+    public override ValueTask<int> NonQueryExecutedAsync(
+        DbCommand command,
+        CommandExecutedEventData eventData,
+        int result,
+        CancellationToken cancellationToken = default)
+    {
+        Observe(command, eventData.Duration, "nonquery");
+        return ValueTask.FromResult(result);
+    }
+
+    public override object? ScalarExecuted(
+        DbCommand command,
+        CommandExecutedEventData eventData,
+        object? result)
+    {
+        Observe(command, eventData.Duration, "scalar");
+        return result;
+    }
+
+    public override ValueTask<object?> ScalarExecutedAsync(
+        DbCommand command,
+        CommandExecutedEventData eventData,
+        object? result,
+        CancellationToken cancellationToken = default)
+    {
+        Observe(command, eventData.Duration, "scalar");
+        return ValueTask.FromResult(result);
+    }
+
+    public override void CommandFailed(
+        DbCommand command,
+        CommandErrorEventData eventData) =>
+        Observe(
+            command,
+            eventData.Duration,
+            "failed",
+            eventData.Exception.GetType().Name);
+
+    public override Task CommandFailedAsync(
+        DbCommand command,
+        CommandErrorEventData eventData,
+        CancellationToken cancellationToken = default)
+    {
+        Observe(
+            command,
+            eventData.Duration,
+            "failed",
+            eventData.Exception.GetType().Name);
+        return Task.CompletedTask;
+    }
+
+    public override void CommandCanceled(
+        DbCommand command,
+        CommandEndEventData eventData) =>
+        Observe(command, eventData.Duration, "canceled", "canceled");
+
+    public override Task CommandCanceledAsync(
+        DbCommand command,
+        CommandEndEventData eventData,
+        CancellationToken cancellationToken = default)
+    {
+        Observe(command, eventData.Duration, "canceled", "canceled");
+        return Task.CompletedTask;
+    }
+
+    private void Observe(
+        DbCommand command,
+        TimeSpan duration,
+        string commandKind,
+        string? errorType = null)
+    {
+        if (!options.Enabled) return;
+
+        var queryName = GetQueryName(command.CommandText);
+        var statementHash = GetStatementHash(command.CommandText);
+        var provider = GetProviderName(command);
+        var traceId = Activity.Current?.TraceId.ToString() ?? "none";
+        var tags = new TagList
+        {
+            { "db.system.name", provider },
+            { "db.operation.name", commandKind },
+            { "db.query.name", queryName }
+        };
+        if (errorType is not null)
+            tags.Add("error.type", errorType);
+
+        var durationMilliseconds = duration.TotalMilliseconds;
+        CommandDuration.Record(durationMilliseconds, tags);
+        if (errorType is not null)
+            FailedCommandCount.Add(1, tags);
+
+        using var activity = ActivitySource.StartActivity(
+            ActivityKind.Client,
+            Activity.Current?.Context ?? default,
+            startTime: DateTimeOffset.UtcNow - duration,
+            name: queryName);
+        if (activity is not null)
+        {
+            activity.SetTag("db.system.name", provider);
+            activity.SetTag("db.operation.name", commandKind);
+            activity.SetTag("db.query.name", queryName);
+            activity.SetTag("db.statement.hash", statementHash);
+            activity.SetTag(
+                "db.namespace",
+                EmptyToNull(command.Connection?.Database));
+            if (options.IncludeSqlText)
+            {
+                activity.SetTag(
+                    "db.query.text",
+                    Truncate(command.CommandText, options.MaximumSqlTextLength));
+            }
+            if (errorType is not null)
+            {
+                activity.SetTag("error.type", errorType);
+                activity.SetStatus(ActivityStatusCode.Error, errorType);
+            }
+            activity.SetEndTime(DateTime.UtcNow);
+        }
+
+        if (errorType is not null)
+        {
+            logger.LogError(
+                "Database command failed after {DurationMs:F1} ms: " +
+                "{QueryName} ({CommandKind}, {Provider}, hash {StatementHash}, " +
+                "error {ErrorType}, trace {TraceId}).",
+                durationMilliseconds,
+                queryName,
+                commandKind,
+                provider,
+                statementHash,
+                errorType,
+                traceId);
+            return;
+        }
+
+        if (durationMilliseconds < options.SlowQueryThresholdMilliseconds)
+            return;
+
+        SlowCommandCount.Add(1, tags);
+        if (options.IncludeSqlText)
+        {
+            logger.LogWarning(
+                "Slow database command took {DurationMs:F1} ms: " +
+                "{QueryName} ({CommandKind}, {Provider}, hash {StatementHash}, " +
+                "trace {TraceId}). " +
+                "SQL template: {SqlTemplate}",
+                durationMilliseconds,
+                queryName,
+                commandKind,
+                provider,
+                statementHash,
+                traceId,
+                Truncate(command.CommandText, options.MaximumSqlTextLength));
+        }
+        else
+        {
+            logger.LogWarning(
+                "Slow database command took {DurationMs:F1} ms: " +
+                "{QueryName} ({CommandKind}, {Provider}, hash {StatementHash}, " +
+                "trace {TraceId}).",
+                durationMilliseconds,
+                queryName,
+                commandKind,
+                provider,
+                statementHash,
+                traceId);
+        }
+    }
+
+    internal static string GetQueryName(string commandText)
+    {
+        using var reader = new StringReader(commandText);
+        while (reader.ReadLine() is { } line)
+        {
+            var trimmed = line.Trim();
+            if (trimmed.Length == 0) continue;
+            if (trimmed.StartsWith("-- ", StringComparison.Ordinal))
+                return Truncate(trimmed[3..].Trim(), 120);
+            return $"{FirstToken(trimmed)}:{GetStatementHash(commandText)}";
+        }
+
+        return $"unknown:{GetStatementHash(commandText)}";
+    }
+
+    internal static string GetStatementHash(string commandText)
+    {
+        var bytes = SHA256.HashData(Encoding.UTF8.GetBytes(commandText));
+        return Convert.ToHexString(bytes.AsSpan(0, 6)).ToLowerInvariant();
+    }
+
+    private static string FirstToken(string value)
+    {
+        var end = value.IndexOfAny([' ', '\t', '\r', '\n', '(']);
+        var token = end < 0 ? value : value[..end];
+        return token.Length == 0
+            ? "command"
+            : token.ToLowerInvariant();
+    }
+
+    private static string GetProviderName(DbCommand command)
+    {
+        var typeName = command.GetType().FullName ?? command.GetType().Name;
+        if (typeName.Contains("MySql", StringComparison.OrdinalIgnoreCase))
+            return "mysql";
+        if (typeName.Contains("Sqlite", StringComparison.OrdinalIgnoreCase))
+            return "sqlite";
+        return "other_sql";
+    }
+
+    private static string? EmptyToNull(string? value) =>
+        string.IsNullOrWhiteSpace(value) ? null : value;
+
+    private static string Truncate(string value, int maximumLength) =>
+        value.Length <= maximumLength
+            ? value
+            : value[..maximumLength];
+}

src/Jiaowu.Api/Infrastructure/Observability/ObservabilityOptions.cs

@@ -0,0 +1,12 @@
+namespace Jiaowu.Api.Infrastructure.Observability;
+
+public sealed class ObservabilityOptions
+{
+    public const string SectionName = "Observability";
+
+    public bool Enabled { get; set; } = true;
+    public string ServiceName { get; set; } = "jiaowu-api";
+    public int SlowQueryThresholdMilliseconds { get; set; } = 500;
+    public bool IncludeSqlText { get; set; }
+    public int MaximumSqlTextLength { get; set; } = 2000;
+}

src/Jiaowu.Api/Infrastructure/Observability/PerformanceReportService.cs

@@ -0,0 +1,556 @@
+using System.Globalization;
+using System.Net.Http.Headers;
+using System.Text.Json;
+using Microsoft.Extensions.Caching.Memory;
+
+namespace Jiaowu.Api.Infrastructure.Observability;
+
+public sealed class PerformanceReportService(
+    HttpClient httpClient,
+    IMemoryCache cache,
+    PerformanceReportingOptions options,
+    ObservabilityOptions observability,
+    ILogger<PerformanceReportService> logger)
+{
+    public async Task<PerformanceReport> GetAsync(
+        string? range,
+        CancellationToken cancellationToken)
+    {
+        var rangeSpec = PerformanceRange.TryParse(range);
+        if (rangeSpec is null)
+            throw new ArgumentOutOfRangeException(
+                nameof(range),
+                "性能报表范围仅支持 15m、1h、24h 或 7d。");
+
+        if (!options.Enabled ||
+            string.IsNullOrWhiteSpace(options.PrometheusBaseUrl))
+        {
+            return PerformanceReport.NotConfigured(
+                rangeSpec.Key,
+                options.GrafanaBaseUrl);
+        }
+
+        var cacheKey = $"performance-report:{rangeSpec.Key}";
+        if (cache.TryGetValue<PerformanceReport>(cacheKey, out var cached))
+            return cached!;
+
+        PerformanceReport report;
+        try
+        {
+            report = await LoadAsync(rangeSpec, cancellationToken);
+        }
+        catch (Exception exception) when (
+            !cancellationToken.IsCancellationRequested)
+        {
+            logger.LogWarning(
+                exception,
+                "Performance report source is unavailable for range {Range}.",
+                rangeSpec.Key);
+            report = PerformanceReport.Unavailable(
+                rangeSpec.Key,
+                options.GrafanaBaseUrl);
+        }
+
+        cache.Set(
+            cacheKey,
+            report,
+            TimeSpan.FromSeconds(options.CacheSeconds));
+        return report;
+    }
+
+    private async Task<PerformanceReport> LoadAsync(
+        PerformanceRange range,
+        CancellationToken cancellationToken)
+    {
+        var now = DateTime.UtcNow;
+        var from = now - range.Duration;
+        var requestCountSelector = Selector(
+            options.RequestDurationMetric + "_count",
+            (options.ServiceLabel, "=", observability.ServiceName));
+        var requestBucketSelector = Selector(
+            options.RequestDurationMetric + "_bucket",
+            (options.ServiceLabel, "=", observability.ServiceName));
+        var errorCountSelector = Selector(
+            options.RequestDurationMetric + "_count",
+            (options.ServiceLabel, "=", observability.ServiceName),
+            ("http_response_status_code", "=~", "5.."));
+        var databaseCountSelector = Selector(
+            options.DatabaseDurationMetric + "_count",
+            (options.ServiceLabel, "=", observability.ServiceName));
+        var databaseBucketSelector = Selector(
+            options.DatabaseDurationMetric + "_bucket",
+            (options.ServiceLabel, "=", observability.ServiceName));
+        var slowDatabaseSelector = Selector(
+            options.SlowDatabaseMetric,
+            (options.ServiceLabel, "=", observability.ServiceName));
+        var failedDatabaseSelector = Selector(
+            options.FailedDatabaseMetric,
+            (options.ServiceLabel, "=", observability.ServiceName));
+
+        var requestCountTask = QueryScalarAsync(
+            $"sum(increase({requestCountSelector}[{range.PrometheusRange}]))",
+            now,
+            cancellationToken);
+        var serverErrorCountTask = QueryScalarAsync(
+            $"sum(increase({errorCountSelector}[{range.PrometheusRange}]))",
+            now,
+            cancellationToken);
+        var requestP95Task = QueryScalarAsync(
+            "histogram_quantile(0.95, " +
+            $"sum by (le) (rate({requestBucketSelector}[{range.RateWindow}]))) " +
+            "* 1000",
+            now,
+            cancellationToken);
+        var databaseP95Task = QueryScalarAsync(
+            "histogram_quantile(0.95, " +
+            $"sum by (le) (rate({databaseBucketSelector}[{range.RateWindow}])))",
+            now,
+            cancellationToken);
+        var slowCountTask = QueryScalarAsync(
+            $"sum(increase({slowDatabaseSelector}[{range.PrometheusRange}]))",
+            now,
+            cancellationToken);
+        var failedCountTask = QueryScalarAsync(
+            $"sum(increase({failedDatabaseSelector}[{range.PrometheusRange}]))",
+            now,
+            cancellationToken);
+        var requestTimelineTask = QueryRangeAsync(
+            $"sum(rate({requestCountSelector}[{range.RateWindow}]))",
+            from,
+            now,
+            range.StepSeconds,
+            cancellationToken);
+        var latencyTimelineTask = QueryRangeAsync(
+            "histogram_quantile(0.95, " +
+            $"sum by (le) (rate({requestBucketSelector}[{range.RateWindow}]))) " +
+            "* 1000",
+            from,
+            now,
+            range.StepSeconds,
+            cancellationToken);
+        var routeLatencyTask = QueryVectorAsync(
+            "histogram_quantile(0.95, " +
+            $"sum by (le, http_route) (rate({requestBucketSelector}" +
+            $"[{range.RateWindow}]))) * 1000",
+            now,
+            cancellationToken);
+        var routeCountTask = QueryVectorAsync(
+            $"sum by (http_route) (increase({requestCountSelector}" +
+            $"[{range.PrometheusRange}]))",
+            now,
+            cancellationToken);
+        var routeErrorTask = QueryVectorAsync(
+            $"sum by (http_route) (increase({errorCountSelector}" +
+            $"[{range.PrometheusRange}]))",
+            now,
+            cancellationToken);
+        var queryLatencyTask = QueryVectorAsync(
+            "histogram_quantile(0.95, " +
+            $"sum by (le, db_query_name) (rate({databaseBucketSelector}" +
+            $"[{range.RateWindow}])))",
+            now,
+            cancellationToken);
+        var queryCountTask = QueryVectorAsync(
+            $"sum by (db_query_name) (increase({databaseCountSelector}" +
+            $"[{range.PrometheusRange}]))",
+            now,
+            cancellationToken);
+        var querySlowTask = QueryVectorAsync(
+            $"sum by (db_query_name) (increase({slowDatabaseSelector}" +
+            $"[{range.PrometheusRange}]))",
+            now,
+            cancellationToken);
+
+        await Task.WhenAll(
+            requestCountTask,
+            serverErrorCountTask,
+            requestP95Task,
+            databaseP95Task,
+            slowCountTask,
+            failedCountTask,
+            requestTimelineTask,
+            latencyTimelineTask,
+            routeLatencyTask,
+            routeCountTask,
+            routeErrorTask,
+            queryLatencyTask,
+            queryCountTask,
+            querySlowTask);
+
+        var requestCount = await requestCountTask;
+        var serverErrorCount = await serverErrorCountTask;
+        double? errorRate = requestCount is > 0 && serverErrorCount.HasValue
+            ? serverErrorCount.Value / requestCount.Value * 100
+            : requestCount == 0
+                ? 0
+                : null;
+        var timeline = MergeTimeline(
+            await requestTimelineTask,
+            await latencyTimelineTask);
+        var endpoints = MergeRanking(
+            await routeLatencyTask,
+            await routeCountTask,
+            await routeErrorTask,
+            "http_route");
+        var databaseQueries = MergeRanking(
+            await queryLatencyTask,
+            await queryCountTask,
+            await querySlowTask,
+            "db_query_name");
+
+        return new PerformanceReport(
+            "ready",
+            range.Key,
+            from,
+            now,
+            DateTime.UtcNow,
+            "prometheus",
+            EmptyToNull(options.GrafanaBaseUrl),
+            null,
+            new PerformanceHeadline(
+                Round(requestCount),
+                Round(await requestP95Task),
+                Round(errorRate),
+                Round(await databaseP95Task),
+                Round(await slowCountTask),
+                Round(await failedCountTask)),
+            timeline,
+            endpoints,
+            databaseQueries);
+    }
+
+    private async Task<double?> QueryScalarAsync(
+        string query,
+        DateTime time,
+        CancellationToken cancellationToken)
+    {
+        var vector = await QueryVectorAsync(
+            query,
+            time,
+            cancellationToken);
+        return vector.FirstOrDefault()?.Value;
+    }
+
+    private async Task<IReadOnlyList<PrometheusSample>> QueryVectorAsync(
+        string query,
+        DateTime time,
+        CancellationToken cancellationToken)
+    {
+        var uri = BuildUri(
+            "api/v1/query",
+            ("query", query),
+            ("time", ToUnixSeconds(time).ToString(
+                CultureInfo.InvariantCulture)));
+        using var document = await SendAsync(uri, cancellationToken);
+        var data = document.RootElement.GetProperty("data");
+        var result = data.GetProperty("result");
+        var samples = new List<PrometheusSample>();
+        foreach (var item in result.EnumerateArray())
+        {
+            var labels = ReadLabels(item.GetProperty("metric"));
+            if (!TryReadValue(item.GetProperty("value"), out var value))
+                continue;
+            samples.Add(new PrometheusSample(labels, value));
+        }
+        return samples;
+    }
+
+    private async Task<IReadOnlyList<PerformanceSeriesPoint>> QueryRangeAsync(
+        string query,
+        DateTime from,
+        DateTime to,
+        int stepSeconds,
+        CancellationToken cancellationToken)
+    {
+        var uri = BuildUri(
+            "api/v1/query_range",
+            ("query", query),
+            ("start", ToUnixSeconds(from).ToString(
+                CultureInfo.InvariantCulture)),
+            ("end", ToUnixSeconds(to).ToString(
+                CultureInfo.InvariantCulture)),
+            ("step", stepSeconds.ToString(CultureInfo.InvariantCulture)));
+        using var document = await SendAsync(uri, cancellationToken);
+        var result = document.RootElement
+            .GetProperty("data")
+            .GetProperty("result");
+        var first = result.EnumerateArray().FirstOrDefault();
+        if (first.ValueKind == JsonValueKind.Undefined ||
+            !first.TryGetProperty("values", out var values))
+            return [];
+
+        var points = new List<PerformanceSeriesPoint>();
+        foreach (var value in values.EnumerateArray())
+        {
+            if (!TryReadValue(value, out var measurement)) continue;
+            var timestamp = value[0].GetDouble();
+            points.Add(new PerformanceSeriesPoint(
+                DateTimeOffset.FromUnixTimeMilliseconds(
+                    checked((long)(timestamp * 1000))).UtcDateTime,
+                measurement));
+        }
+        return points;
+    }
+
+    private async Task<JsonDocument> SendAsync(
+        Uri uri,
+        CancellationToken cancellationToken)
+    {
+        using var request = new HttpRequestMessage(HttpMethod.Get, uri);
+        if (!string.IsNullOrWhiteSpace(options.BearerToken))
+        {
+            request.Headers.Authorization =
+                new AuthenticationHeaderValue("Bearer", options.BearerToken);
+        }
+        using var response = await httpClient.SendAsync(
+            request,
+            HttpCompletionOption.ResponseHeadersRead,
+            cancellationToken);
+        response.EnsureSuccessStatusCode();
+        await using var stream = await response.Content.ReadAsStreamAsync(
+            cancellationToken);
+        var document = await JsonDocument.ParseAsync(
+            stream,
+            cancellationToken: cancellationToken);
+        if (!document.RootElement.TryGetProperty("status", out var status) ||
+            status.GetString() != "success")
+        {
+            document.Dispose();
+            throw new InvalidOperationException(
+                "Prometheus 返回了非成功查询状态。");
+        }
+        return document;
+    }
+
+    private Uri BuildUri(
+        string relativePath,
+        params (string Key, string Value)[] parameters)
+    {
+        var baseUri = new Uri(
+            options.PrometheusBaseUrl.TrimEnd('/') + "/",
+            UriKind.Absolute);
+        var query = string.Join(
+            "&",
+            parameters.Select(parameter =>
+                $"{Uri.EscapeDataString(parameter.Key)}=" +
+                $"{Uri.EscapeDataString(parameter.Value)}"));
+        return new Uri(baseUri, $"{relativePath}?{query}");
+    }
+
+    private static string Selector(
+        string metric,
+        params (string Label, string Operator, string Value)[] filters)
+    {
+        var matchers = string.Join(
+            ",",
+            filters.Select(filter =>
+                $"{filter.Label}{filter.Operator}\"" +
+                $"{EscapePrometheusValue(filter.Value)}\""));
+        return $"{metric}{{{matchers}}}";
+    }
+
+    private static string EscapePrometheusValue(string value) =>
+        value.Replace("\\", "\\\\", StringComparison.Ordinal)
+            .Replace("\"", "\\\"", StringComparison.Ordinal)
+            .Replace("\r", "\\r", StringComparison.Ordinal)
+            .Replace("\n", "\\n", StringComparison.Ordinal);
+
+    private static IReadOnlyDictionary<string, string> ReadLabels(
+        JsonElement metric)
+    {
+        var result = new Dictionary<string, string>(
+            StringComparer.Ordinal);
+        foreach (var property in metric.EnumerateObject())
+            result[property.Name] = property.Value.GetString() ?? "";
+        return result;
+    }
+
+    private static bool TryReadValue(
+        JsonElement value,
+        out double measurement)
+    {
+        measurement = 0;
+        if (value.ValueKind != JsonValueKind.Array ||
+            value.GetArrayLength() < 2)
+            return false;
+        var raw = value[1].GetString();
+        return double.TryParse(
+                   raw,
+                   NumberStyles.Float,
+                   CultureInfo.InvariantCulture,
+                   out measurement) &&
+               double.IsFinite(measurement);
+    }
+
+    private static IReadOnlyList<PerformanceTimelinePoint> MergeTimeline(
+        IReadOnlyList<PerformanceSeriesPoint> requestRate,
+        IReadOnlyList<PerformanceSeriesPoint> latency)
+    {
+        var points = new SortedDictionary<DateTime, PerformanceTimelinePoint>();
+        foreach (var point in requestRate)
+        {
+            points[point.Timestamp] = new PerformanceTimelinePoint(
+                point.Timestamp,
+                Math.Round(point.Value, 3),
+                null);
+        }
+        foreach (var point in latency)
+        {
+            points.TryGetValue(point.Timestamp, out var existing);
+            points[point.Timestamp] = new PerformanceTimelinePoint(
+                point.Timestamp,
+                existing?.RequestsPerSecond,
+                Math.Round(point.Value, 2));
+        }
+        return points.Values.ToArray();
+    }
+
+    private static IReadOnlyList<PerformanceRankingItem> MergeRanking(
+        IReadOnlyList<PrometheusSample> latency,
+        IReadOnlyList<PrometheusSample> count,
+        IReadOnlyList<PrometheusSample> exceptional,
+        string label)
+    {
+        var names = latency
+            .Concat(count)
+            .Concat(exceptional)
+            .Select(item => item.Labels.GetValueOrDefault(label))
+            .Where(name => !string.IsNullOrWhiteSpace(name))
+            .Distinct(StringComparer.Ordinal)
+            .ToArray();
+        var items = names.Select(name =>
+        {
+            var latencyValue = FindValue(latency, label, name);
+            var countValue = FindValue(count, label, name);
+            var exceptionalValue = FindValue(exceptional, label, name);
+            return new PerformanceRankingItem(
+                name!,
+                Round(latencyValue),
+                Round(countValue),
+                Round(exceptionalValue));
+        });
+        return items
+            .OrderByDescending(item => item.P95Milliseconds ?? -1)
+            .ThenByDescending(item => item.RequestCount ?? -1)
+            .Take(10)
+            .ToArray();
+    }
+
+    private static double? FindValue(
+        IReadOnlyList<PrometheusSample> samples,
+        string label,
+        string? name) =>
+        samples.FirstOrDefault(item =>
+            item.Labels.GetValueOrDefault(label) == name)?.Value;
+
+    private static double ToUnixSeconds(DateTime value) =>
+        new DateTimeOffset(
+            DateTime.SpecifyKind(value, DateTimeKind.Utc)).ToUnixTimeMilliseconds()
+        / 1000d;
+
+    private static double? Round(double? value) =>
+        value.HasValue && double.IsFinite(value.Value)
+            ? Math.Round(value.Value, 2)
+            : null;
+
+    private static string? EmptyToNull(string? value) =>
+        string.IsNullOrWhiteSpace(value) ? null : value;
+
+    private sealed record PrometheusSample(
+        IReadOnlyDictionary<string, string> Labels,
+        double Value);
+
+    private sealed record PerformanceSeriesPoint(
+        DateTime Timestamp,
+        double Value);
+}
+
+public sealed record PerformanceHeadline(
+    double? RequestCount,
+    double? RequestP95Milliseconds,
+    double? ServerErrorRatePercent,
+    double? DatabaseP95Milliseconds,
+    double? SlowDatabaseCommandCount,
+    double? FailedDatabaseCommandCount);
+
+public sealed record PerformanceTimelinePoint(
+    DateTime Timestamp,
+    double? RequestsPerSecond,
+    double? RequestP95Milliseconds);
+
+public sealed record PerformanceRankingItem(
+    string Name,
+    double? P95Milliseconds,
+    double? RequestCount,
+    double? ExceptionalCount);
+
+public sealed record PerformanceReport(
+    string Status,
+    string Range,
+    DateTime? From,
+    DateTime? To,
+    DateTime GeneratedAt,
+    string DataSource,
+    string? DashboardUrl,
+    string? Detail,
+    PerformanceHeadline? Headline,
+    IReadOnlyList<PerformanceTimelinePoint> Timeline,
+    IReadOnlyList<PerformanceRankingItem> Endpoints,
+    IReadOnlyList<PerformanceRankingItem> DatabaseQueries)
+{
+    public static PerformanceReport NotConfigured(
+        string range,
+        string? dashboardUrl) =>
+        Empty(
+            "not_configured",
+            range,
+            dashboardUrl,
+            "尚未配置 Prometheus 数据源。请先部署指标存储并设置 " +
+            "PerformanceReporting__PrometheusBaseUrl。");
+
+    public static PerformanceReport Unavailable(
+        string range,
+        string? dashboardUrl) =>
+        Empty(
+            "unavailable",
+            range,
+            dashboardUrl,
+            "性能数据源暂时不可用。系统业务不受影响，请检查 Prometheus 与网络配置。");
+
+    private static PerformanceReport Empty(
+        string status,
+        string range,
+        string? dashboardUrl,
+        string detail) =>
+        new(
+            status,
+            range,
+            null,
+            null,
+            DateTime.UtcNow,
+            "prometheus",
+            string.IsNullOrWhiteSpace(dashboardUrl) ? null : dashboardUrl,
+            detail,
+            null,
+            [],
+            [],
+            []);
+}
+
+internal sealed record PerformanceRange(
+    string Key,
+    TimeSpan Duration,
+    string PrometheusRange,
+    string RateWindow,
+    int StepSeconds)
+{
+    public static PerformanceRange? TryParse(string? value) =>
+        value?.Trim().ToLowerInvariant() switch
+        {
+            "15m" => new("15m", TimeSpan.FromMinutes(15), "15m", "1m", 30),
+            "1h" => new("1h", TimeSpan.FromHours(1), "1h", "5m", 60),
+            "24h" => new("24h", TimeSpan.FromHours(24), "24h", "15m", 900),
+            "7d" => new("7d", TimeSpan.FromDays(7), "7d", "1h", 3600),
+            _ => null
+        };
+}

src/Jiaowu.Api/Infrastructure/Observability/PerformanceReportingOptions.cs

@@ -0,0 +1,31 @@
+using System.Text.RegularExpressions;
+
+namespace Jiaowu.Api.Infrastructure.Observability;
+
+public sealed partial class PerformanceReportingOptions
+{
+    public const string SectionName = "PerformanceReporting";
+
+    public bool Enabled { get; set; }
+    public string PrometheusBaseUrl { get; set; } = "";
+    public string BearerToken { get; set; } = "";
+    public string GrafanaBaseUrl { get; set; } = "";
+    public int CacheSeconds { get; set; } = 30;
+    public int TimeoutSeconds { get; set; } = 10;
+    public string ServiceLabel { get; set; } = "service_name";
+    public string RequestDurationMetric { get; set; } =
+        "http_server_request_duration_seconds";
+    public string DatabaseDurationMetric { get; set; } =
+        "jiaowu_db_command_duration_milliseconds";
+    public string SlowDatabaseMetric { get; set; } =
+        "jiaowu_db_command_slow_total";
+    public string FailedDatabaseMetric { get; set; } =
+        "jiaowu_db_command_failed_total";
+
+    public static bool IsMetricOrLabelName(string value) =>
+        !string.IsNullOrWhiteSpace(value) &&
+        PrometheusNamePattern().IsMatch(value);
+
+    [GeneratedRegex("^[a-zA-Z_:][a-zA-Z0-9_:]*$")]
+    private static partial Regex PrometheusNamePattern();
+}

src/Jiaowu.Api/Infrastructure/OfficialDocuments/OfficialDocumentOptions.cs

@@ -0,0 +1,12 @@
+namespace Jiaowu.Api.Infrastructure.OfficialDocuments;
+
+public sealed class OfficialDocumentOptions
+{
+    public const string SectionName = "OfficialDocuments";
+
+    public string InstitutionName { get; set; } = "明序大学";
+    public string IssuingOffice { get; set; } = "教务处";
+    public string DocumentNumberPrefix { get; set; } = "MXU";
+    public string? PublicBaseUrl { get; set; }
+    public string? FontPath { get; set; }
+}

src/Jiaowu.Api/Infrastructure/OfficialDocuments/OfficialDocumentPdfGenerator.cs

@@ -0,0 +1,409 @@
+using System.Security.Cryptography;
+using QRCoder;
+using SkiaSharp;
+
+namespace Jiaowu.Api.Infrastructure.OfficialDocuments;
+
+public interface IOfficialDocumentPdfGenerator
+{
+    GeneratedOfficialDocument Generate(
+        OfficialDocumentSnapshot snapshot,
+        string verificationUrl);
+}
+
+public sealed class OfficialDocumentPdfGenerator(
+    OfficialDocumentOptions options) : IOfficialDocumentPdfGenerator
+{
+    private const float PageWidth = 595;
+    private const float PageHeight = 842;
+    private const float Margin = 44;
+    private const float ContentWidth = PageWidth - Margin * 2;
+    private static readonly SKColor Ink = new(31, 48, 65);
+    private static readonly SKColor Muted = new(91, 107, 120);
+    private static readonly SKColor Accent = new(26, 91, 82);
+    private static readonly SKColor Pale = new(236, 244, 242);
+    private static readonly SKColor Rule = new(208, 219, 220);
+
+    public GeneratedOfficialDocument Generate(
+        OfficialDocumentSnapshot snapshot,
+        string verificationUrl)
+    {
+        using var typeface = ResolveTypeface();
+        using var stream = new MemoryStream();
+        using (var document = SKDocument.CreatePdf(stream))
+        {
+            if (snapshot.Type == Domain.Academic.OfficialDocumentType.Transcript)
+                DrawTranscript(document, typeface, snapshot, verificationUrl);
+            else
+                DrawStatusCertificate(document, typeface, snapshot, verificationUrl);
+            document.Close();
+        }
+
+        var content = stream.ToArray();
+        var hash = Convert.ToHexString(SHA256.HashData(content)).ToLowerInvariant();
+        return new GeneratedOfficialDocument(content, hash);
+    }
+
+    private void DrawTranscript(
+        SKDocument document,
+        SKTypeface typeface,
+        OfficialDocumentSnapshot snapshot,
+        string verificationUrl)
+    {
+        const int rowsPerPage = 19;
+        var pageCount = Math.Max(1, (int)Math.Ceiling(snapshot.Grades.Count / (double)rowsPerPage));
+        for (var pageIndex = 0; pageIndex < pageCount; pageIndex++)
+        {
+            using var canvas = document.BeginPage(PageWidth, PageHeight);
+            DrawPageFrame(canvas);
+            DrawHeader(canvas, typeface, snapshot, "官方电子成绩单", "OFFICIAL ACADEMIC TRANSCRIPT");
+
+            var y = 145f;
+            if (pageIndex == 0)
+            {
+                y = DrawStudentSummary(canvas, typeface, snapshot.Student, y);
+                y = DrawTranscriptSummary(canvas, typeface, snapshot, y + 12);
+            }
+            else
+            {
+                DrawText(canvas, typeface, $"{snapshot.Student.Name} · {snapshot.Student.StudentNumber}",
+                    Margin, y, 10, Muted);
+                y += 20;
+            }
+
+            var rows = snapshot.Grades.Skip(pageIndex * rowsPerPage).Take(rowsPerPage).ToArray();
+            y = DrawGradeTable(canvas, typeface, rows, y + 14);
+
+            if (pageIndex == pageCount - 1)
+                DrawVerificationBlock(canvas, typeface, snapshot, verificationUrl, Math.Min(y + 18, 685));
+
+            DrawFooter(canvas, typeface, snapshot, pageIndex + 1, pageCount);
+            document.EndPage();
+        }
+    }
+
+    private void DrawStatusCertificate(
+        SKDocument document,
+        SKTypeface typeface,
+        OfficialDocumentSnapshot snapshot,
+        string verificationUrl)
+    {
+        using var canvas = document.BeginPage(PageWidth, PageHeight);
+        DrawPageFrame(canvas);
+        DrawHeader(canvas, typeface, snapshot, "学籍状态证明", "CERTIFICATE OF STUDENT STATUS");
+
+        var student = snapshot.Student;
+        var statusText = student.Status switch
+        {
+            "在读" => "现为我校在读学生",
+            "休学" => "现为我校注册学生，当前处于休学状态",
+            "已毕业" => "曾在我校就读，现已毕业",
+            "退学" => "曾在我校就读，现已办理退学",
+            _ => $"在我校的学籍状态为“{student.Status}”"
+        };
+
+        DrawText(canvas, typeface, "证  明", PageWidth / 2, 215, 25, Ink, SKTextAlign.Center, true);
+        var body = $"兹证明，{student.Name}（学号：{student.StudentNumber}），" +
+                   $"于 {student.EnrollmentDate:yyyy年M月d日} 入学，" +
+                   $"就读于{student.CollegeName}{student.MajorName}专业，行政班级为{student.ClassName}，" +
+                   $"{statusText}。";
+        var y = 285f;
+        foreach (var line in WrapText(typeface, body, 16, 448))
+        {
+            DrawText(canvas, typeface, line, 74, y, 16, Ink);
+            y += 32;
+        }
+
+        if (!string.IsNullOrWhiteSpace(snapshot.Purpose))
+        {
+            DrawText(canvas, typeface, $"用途：{snapshot.Purpose}", 74, y + 14, 11, Muted);
+            y += 30;
+        }
+
+        DrawText(canvas, typeface, "特此证明。", 74, y + 28, 16, Ink);
+        DrawText(canvas, typeface, snapshot.InstitutionName, 435, y + 100, 14, Ink,
+            SKTextAlign.Center, true);
+        DrawText(canvas, typeface, snapshot.IssuingOffice, 435, y + 126, 12, Ink,
+            SKTextAlign.Center);
+        DrawText(canvas, typeface, snapshot.IssuedAt.ToLocalTime().ToString("yyyy年M月d日"),
+            435, y + 150, 11, Muted, SKTextAlign.Center);
+
+        DrawVerificationBlock(canvas, typeface, snapshot, verificationUrl, 625);
+        DrawFooter(canvas, typeface, snapshot, 1, 1);
+        document.EndPage();
+    }
+
+    private static void DrawPageFrame(SKCanvas canvas)
+    {
+        canvas.Clear(SKColors.White);
+        using var border = new SKPaint { Color = Accent, Style = SKPaintStyle.Stroke, StrokeWidth = 1.4f };
+        using var inner = new SKPaint { Color = Rule, Style = SKPaintStyle.Stroke, StrokeWidth = .55f };
+        canvas.DrawRect(22, 22, PageWidth - 44, PageHeight - 44, border);
+        canvas.DrawRect(27, 27, PageWidth - 54, PageHeight - 54, inner);
+    }
+
+    private static void DrawHeader(
+        SKCanvas canvas,
+        SKTypeface typeface,
+        OfficialDocumentSnapshot snapshot,
+        string title,
+        string englishTitle)
+    {
+        DrawText(canvas, typeface, snapshot.InstitutionName, Margin, 66, 16, Accent, bold: true);
+        DrawText(canvas, typeface, snapshot.IssuingOffice, PageWidth - Margin, 66, 10, Muted,
+            SKTextAlign.Right);
+        DrawText(canvas, typeface, title, PageWidth / 2, 99, 23, Ink, SKTextAlign.Center, true);
+        DrawText(canvas, typeface, englishTitle, PageWidth / 2, 119, 8.5f, Muted,
+            SKTextAlign.Center);
+        using var rule = new SKPaint { Color = Accent, StrokeWidth = 1.2f };
+        canvas.DrawLine(Margin, 132, PageWidth - Margin, 132, rule);
+    }
+
+    private static float DrawStudentSummary(
+        SKCanvas canvas,
+        SKTypeface typeface,
+        OfficialStudentSnapshot student,
+        float y)
+    {
+        using var fill = new SKPaint { Color = Pale, Style = SKPaintStyle.Fill };
+        canvas.DrawRoundRect(new SKRect(Margin, y, PageWidth - Margin, y + 86), 5, 5, fill);
+        DrawLabelValue(canvas, typeface, "姓名", student.Name, Margin + 15, y + 24);
+        DrawLabelValue(canvas, typeface, "学号", student.StudentNumber, 210, y + 24);
+        DrawLabelValue(canvas, typeface, "学籍状态", student.Status, 404, y + 24);
+        DrawLabelValue(canvas, typeface, "学院", student.CollegeName, Margin + 15, y + 57);
+        DrawLabelValue(canvas, typeface, "专业", student.MajorName, 210, y + 57);
+        DrawLabelValue(canvas, typeface, "班级", student.ClassName, 404, y + 57);
+        return y + 86;
+    }
+
+    private static float DrawTranscriptSummary(
+        SKCanvas canvas,
+        SKTypeface typeface,
+        OfficialDocumentSnapshot snapshot,
+        float y)
+    {
+        var values = new[]
+        {
+            ("课程门数", snapshot.Grades.Count.ToString()),
+            ("修读学分", FormatDecimal(snapshot.TotalCredits)),
+            ("获得学分", FormatDecimal(snapshot.EarnedCredits)),
+            ("平均绩点", snapshot.GradePointAverage?.ToString("0.00") ?? "-")
+        };
+        var width = ContentWidth / values.Length;
+        for (var i = 0; i < values.Length; i++)
+        {
+            var center = Margin + width * i + width / 2;
+            DrawText(canvas, typeface, values[i].Item1, center, y + 12, 8.5f, Muted,
+                SKTextAlign.Center);
+            DrawText(canvas, typeface, values[i].Item2, center, y + 33, 15, Accent,
+                SKTextAlign.Center, true);
+        }
+        return y + 42;
+    }
+
+    private static float DrawGradeTable(
+        SKCanvas canvas,
+        SKTypeface typeface,
+        IReadOnlyList<OfficialTranscriptRow> rows,
+        float y)
+    {
+        var widths = new[] { 96f, 64f, 160f, 48f, 55f, 45f, 39f };
+        var headers = new[] { "学期", "课程代码", "课程名称", "学分", "成绩", "绩点", "状态" };
+        const float headerHeight = 27;
+        const float rowHeight = 24;
+        using var headerPaint = new SKPaint { Color = Accent, Style = SKPaintStyle.Fill };
+        using var stripe = new SKPaint { Color = new SKColor(247, 249, 249), Style = SKPaintStyle.Fill };
+        using var rule = new SKPaint { Color = Rule, StrokeWidth = .5f };
+        canvas.DrawRect(Margin, y, ContentWidth, headerHeight, headerPaint);
+
+        var x = Margin;
+        for (var i = 0; i < headers.Length; i++)
+        {
+            DrawText(canvas, typeface, headers[i], x + widths[i] / 2, y + 18, 8.5f,
+                SKColors.White, SKTextAlign.Center, true);
+            x += widths[i];
+        }
+
+        for (var rowIndex = 0; rowIndex < rows.Count; rowIndex++)
+        {
+            var row = rows[rowIndex];
+            var rowY = y + headerHeight + rowIndex * rowHeight;
+            if (rowIndex % 2 == 1)
+                canvas.DrawRect(Margin, rowY, ContentWidth, rowHeight, stripe);
+            canvas.DrawLine(Margin, rowY + rowHeight, PageWidth - Margin, rowY + rowHeight, rule);
+            var values = new[]
+            {
+                row.AcademicTerm,
+                row.CourseCode,
+                Ellipsize(typeface, row.CourseName, 8.5f, widths[2] - 8),
+                FormatDecimal(row.Credits),
+                row.Score?.ToString("0.#") ?? "-",
+                row.GradePoint?.ToString("0.0#") ?? "-",
+                row.ExamStatus
+            };
+            x = Margin;
+            for (var i = 0; i < values.Length; i++)
+            {
+                DrawText(canvas, typeface, values[i], x + widths[i] / 2, rowY + 16, 8.5f,
+                    Ink, SKTextAlign.Center);
+                x += widths[i];
+            }
+        }
+        return y + headerHeight + rows.Count * rowHeight;
+    }
+
+    private static void DrawVerificationBlock(
+        SKCanvas canvas,
+        SKTypeface typeface,
+        OfficialDocumentSnapshot snapshot,
+        string verificationUrl,
+        float y)
+    {
+        using var fill = new SKPaint { Color = Pale, Style = SKPaintStyle.Fill };
+        canvas.DrawRoundRect(new SKRect(Margin, y, PageWidth - Margin, y + 84), 5, 5, fill);
+        DrawQrCode(canvas, verificationUrl, Margin + 10, y + 7, 70);
+        DrawText(canvas, typeface, "扫码验真", Margin + 94, y + 22, 11, Accent, bold: true);
+        DrawText(canvas, typeface, $"凭证编号：{snapshot.DocumentNumber}", Margin + 94, y + 43, 9.5f, Ink);
+        DrawText(canvas, typeface, "二维码指向本系统公开验真页；失效或重签后状态会实时更新。",
+            Margin + 94, y + 62, 8.5f, Muted);
+    }
+
+    private static void DrawFooter(
+        SKCanvas canvas,
+        SKTypeface typeface,
+        OfficialDocumentSnapshot snapshot,
+        int page,
+        int pageCount)
+    {
+        using var rule = new SKPaint { Color = Rule, StrokeWidth = .6f };
+        canvas.DrawLine(Margin, 790, PageWidth - Margin, 790, rule);
+        DrawText(canvas, typeface,
+            $"签发：{snapshot.IssuedByName} · {snapshot.IssuedAt.ToLocalTime():yyyy-MM-dd HH:mm}",
+            Margin, 807, 7.5f, Muted);
+        DrawText(canvas, typeface, $"第 {page} / {pageCount} 页", PageWidth - Margin, 807, 7.5f,
+            Muted, SKTextAlign.Right);
+    }
+
+    private static void DrawLabelValue(
+        SKCanvas canvas,
+        SKTypeface typeface,
+        string label,
+        string value,
+        float x,
+        float y)
+    {
+        DrawText(canvas, typeface, label, x, y, 8, Muted);
+        DrawText(canvas, typeface, value, x + 42, y, 10, Ink, bold: true);
+    }
+
+    private static void DrawQrCode(SKCanvas canvas, string content, float x, float y, float size)
+    {
+        using var generator = new QRCodeGenerator();
+        using var data = generator.CreateQrCode(content, QRCodeGenerator.ECCLevel.Q);
+        var modules = data.ModuleMatrix;
+        const int quiet = 4;
+        var moduleSize = size / (modules.Count + quiet * 2);
+        using var paint = new SKPaint { Color = Ink, Style = SKPaintStyle.Fill, IsAntialias = false };
+        for (var row = 0; row < modules.Count; row++)
+        for (var column = 0; column < modules[row].Count; column++)
+        {
+            if (!modules[row][column]) continue;
+            canvas.DrawRect(
+                x + (column + quiet) * moduleSize,
+                y + (row + quiet) * moduleSize,
+                moduleSize + .08f,
+                moduleSize + .08f,
+                paint);
+        }
+    }
+
+    private static void DrawText(
+        SKCanvas canvas,
+        SKTypeface typeface,
+        string text,
+        float x,
+        float y,
+        float size,
+        SKColor color,
+        SKTextAlign align = SKTextAlign.Left,
+        bool bold = false)
+    {
+        using var font = new SKFont(typeface, size) { Embolden = bold };
+        using var paint = new SKPaint { Color = color, IsAntialias = true };
+        canvas.DrawText(text, x, y, align, font, paint);
+    }
+
+    private static IReadOnlyList<string> WrapText(
+        SKTypeface typeface,
+        string text,
+        float size,
+        float maxWidth)
+    {
+        using var font = new SKFont(typeface, size);
+        var lines = new List<string>();
+        var current = "";
+        foreach (var character in text)
+        {
+            var candidate = current + character;
+            if (current.Length > 0 && font.MeasureText(candidate) > maxWidth)
+            {
+                var breakIndex = current.LastIndexOfAny([' ', '，', '。', '；', '：', '、']);
+                if (breakIndex >= current.Length / 2)
+                {
+                    lines.Add(current[..(breakIndex + 1)].TrimEnd());
+                    current = current[(breakIndex + 1)..].TrimStart() + character;
+                }
+                else
+                {
+                    lines.Add(current);
+                    current = character.ToString();
+                }
+            }
+            else
+            {
+                current = candidate;
+            }
+        }
+        if (current.Length > 0) lines.Add(current);
+        return lines;
+    }
+
+    private static string Ellipsize(
+        SKTypeface typeface,
+        string text,
+        float size,
+        float maxWidth)
+    {
+        using var font = new SKFont(typeface, size);
+        if (font.MeasureText(text) <= maxWidth) return text;
+        var value = text;
+        while (value.Length > 1 && font.MeasureText(value + "…") > maxWidth)
+            value = value[..^1];
+        return value + "…";
+    }
+
+    private SKTypeface ResolveTypeface()
+    {
+        var candidates = new[]
+        {
+            options.FontPath,
+            Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Fonts), "simhei.ttf"),
+            Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Fonts), "msyh.ttc"),
+            "/usr/share/fonts/noto/NotoSansCJK-Regular.ttc",
+            "/usr/share/fonts/noto-cjk/NotoSansCJK-Regular.ttc"
+        };
+        foreach (var path in candidates.Where(x => !string.IsNullOrWhiteSpace(x)))
+        {
+            if (!File.Exists(path)) continue;
+            var typeface = SKTypeface.FromFile(path);
+            if (typeface is not null) return typeface;
+        }
+
+        var fallback = SKTypeface.FromFamilyName("Microsoft YaHei") ??
+                       SKTypeface.FromFamilyName("Noto Sans CJK SC");
+        return fallback ?? throw new InvalidOperationException(
+            "未找到可用于官方 PDF 的中文字体。请配置 OfficialDocuments:FontPath。");
+    }
+
+    private static string FormatDecimal(decimal value) => value.ToString("0.##");
+}

src/Jiaowu.Api/Infrastructure/OfficialDocuments/OfficialDocumentService.cs

@@ -0,0 +1,165 @@
+using System.Security.Cryptography;
+using System.Text;
+using System.Text.Json;
+using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+
+namespace Jiaowu.Api.Infrastructure.OfficialDocuments;
+
+public sealed class OfficialDocumentService(
+    AppDbContext db,
+    OfficialDocumentOptions options,
+    IOfficialDocumentPdfGenerator pdfGenerator)
+{
+    private static readonly JsonSerializerOptions SnapshotJsonOptions = new(JsonSerializerDefaults.Web);
+
+    public async Task<OfficialDocument> CreateAsync(
+        Guid studentId,
+        OfficialDocumentType type,
+        string? purpose,
+        Guid issuedByUserId,
+        string issuedByName,
+        string verificationBaseUrl,
+        Guid? reissuedFromDocumentId,
+        CancellationToken cancellationToken)
+    {
+        var student = await db.Students.AsNoTracking()
+            .Where(x => x.Id == studentId)
+            .Select(x => new
+            {
+                x.StudentNumber,
+                x.Name,
+                x.Gender,
+                x.EnrollmentYear,
+                x.EnrollmentDate,
+                x.Status,
+                CollegeName = x.AdministrativeClass!.Major!.College!.Name,
+                MajorName = x.AdministrativeClass.Major.Name,
+                ClassName = x.AdministrativeClass.Name
+            })
+            .SingleOrDefaultAsync(cancellationToken)
+            ?? throw new OfficialDocumentValidationException("学生档案不存在。");
+
+        var grades = type == OfficialDocumentType.Transcript
+            ? await db.GradeRecords.AsNoTracking()
+                .Where(x =>
+                    x.StudentId == studentId &&
+                    x.GradeSheet!.Status == GradeSheetStatus.Published)
+                .OrderBy(x => x.GradeSheet!.TeachingTask!.AcademicTerm!.StartDate)
+                .ThenBy(x => x.GradeSheet!.TeachingTask!.Course!.Code)
+                .Select(x => new OfficialTranscriptRow(
+                    x.GradeSheet!.TeachingTask!.AcademicTerm!.Name,
+                    x.GradeSheet.TeachingTask.Course!.Code,
+                    x.GradeSheet.TeachingTask.Course.Name,
+                    x.GradeSheet.TeachingTask.Course.Credits,
+                    x.TotalScore,
+                    x.GradePoint,
+                    GradeExamStatusLabel(x.ExamStatus)))
+                .ToListAsync(cancellationToken)
+            : [];
+
+        if (type == OfficialDocumentType.Transcript && grades.Count == 0)
+            throw new OfficialDocumentValidationException("该学生暂无已发布成绩，不能签发官方成绩单。");
+
+        var issuedAt = DateTime.UtcNow;
+        var documentNumber = CreateDocumentNumber(type, issuedAt);
+        var verificationCode = CreateVerificationCode();
+        var studentSnapshot = new OfficialStudentSnapshot(
+            student.StudentNumber,
+            student.Name,
+            GenderLabel(student.Gender),
+            student.CollegeName,
+            student.MajorName,
+            student.ClassName,
+            student.EnrollmentYear,
+            student.EnrollmentDate,
+            StudentStatusLabel(student.Status));
+        var totalCredits = grades.Sum(x => x.Credits);
+        var passedGrades = grades
+            .Where(x => x.Score >= 60 || x.ExamStatus == "免修")
+            .ToArray();
+        var gpaGrades = grades.Where(x => x.GradePoint.HasValue).ToArray();
+        var gpaCredits = gpaGrades.Sum(x => x.Credits);
+        var gpa = gpaCredits > 0
+            ? gpaGrades.Sum(x => x.GradePoint!.Value * x.Credits) / gpaCredits
+            : (decimal?)null;
+        var snapshot = new OfficialDocumentSnapshot(
+            options.InstitutionName,
+            options.IssuingOffice,
+            documentNumber,
+            type,
+            issuedAt,
+            issuedByName,
+            string.IsNullOrWhiteSpace(purpose) ? null : purpose.Trim(),
+            studentSnapshot,
+            grades,
+            totalCredits,
+            passedGrades.Sum(x => x.Credits),
+            gpa);
+        var verificationUrl = $"{verificationBaseUrl.TrimEnd('/')}/verify/{verificationCode}";
+        var generated = pdfGenerator.Generate(snapshot, verificationUrl);
+
+        return new OfficialDocument
+        {
+            DocumentNumber = documentNumber,
+            VerificationCodeHash = HashVerificationCode(verificationCode),
+            Type = type,
+            Status = OfficialDocumentStatus.Valid,
+            StudentId = studentId,
+            IssuedByUserId = issuedByUserId,
+            IssuedAt = issuedAt,
+            Purpose = snapshot.Purpose,
+            SnapshotJson = JsonSerializer.Serialize(snapshot, SnapshotJsonOptions),
+            PdfContent = generated.Content,
+            PdfSha256 = generated.Sha256,
+            ReissuedFromDocumentId = reissuedFromDocumentId
+        };
+    }
+
+    public static string HashVerificationCode(string verificationCode) =>
+        Convert.ToHexString(SHA256.HashData(Encoding.UTF8.GetBytes(verificationCode)))
+            .ToLowerInvariant();
+
+    public static OfficialDocumentSnapshot DeserializeSnapshot(string json) =>
+        JsonSerializer.Deserialize<OfficialDocumentSnapshot>(json, SnapshotJsonOptions)
+        ?? throw new InvalidOperationException("官方凭证快照无法读取。");
+
+    private string CreateDocumentNumber(OfficialDocumentType type, DateTime issuedAt)
+    {
+        var typeCode = type == OfficialDocumentType.Transcript ? "TR" : "SC";
+        var random = Convert.ToHexString(RandomNumberGenerator.GetBytes(6));
+        return $"{options.DocumentNumberPrefix}-{typeCode}-{issuedAt:yyyyMMdd}-{random}";
+    }
+
+    private static string CreateVerificationCode() =>
+        Convert.ToHexString(RandomNumberGenerator.GetBytes(24)).ToLowerInvariant();
+
+    private static string GenderLabel(Gender value) => value switch
+    {
+        Gender.Male => "男",
+        Gender.Female => "女",
+        _ => "未登记"
+    };
+
+    private static string StudentStatusLabel(StudentStatus value) => value switch
+    {
+        StudentStatus.Active => "在读",
+        StudentStatus.Suspended => "休学",
+        StudentStatus.Graduated => "已毕业",
+        StudentStatus.Withdrawn => "退学",
+        _ => "未知"
+    };
+
+    private static string GradeExamStatusLabel(GradeExamStatus value) => value switch
+    {
+        GradeExamStatus.Normal => "正常",
+        GradeExamStatus.Absent => "缺考",
+        GradeExamStatus.Deferred => "缓考",
+        GradeExamStatus.Exempt => "免修",
+        GradeExamStatus.Makeup => "补考",
+        _ => "未知"
+    };
+}
+
+public sealed class OfficialDocumentValidationException(string message) : Exception(message);

src/Jiaowu.Api/Infrastructure/OfficialDocuments/OfficialDocumentSnapshots.cs

@@ -0,0 +1,41 @@
+using Jiaowu.Api.Domain.Academic;
+
+namespace Jiaowu.Api.Infrastructure.OfficialDocuments;
+
+public sealed record OfficialDocumentSnapshot(
+    string InstitutionName,
+    string IssuingOffice,
+    string DocumentNumber,
+    OfficialDocumentType Type,
+    DateTime IssuedAt,
+    string IssuedByName,
+    string? Purpose,
+    OfficialStudentSnapshot Student,
+    IReadOnlyList<OfficialTranscriptRow> Grades,
+    decimal TotalCredits,
+    decimal EarnedCredits,
+    decimal? GradePointAverage);
+
+public sealed record OfficialStudentSnapshot(
+    string StudentNumber,
+    string Name,
+    string Gender,
+    string CollegeName,
+    string MajorName,
+    string ClassName,
+    int EnrollmentYear,
+    DateOnly EnrollmentDate,
+    string Status);
+
+public sealed record OfficialTranscriptRow(
+    string AcademicTerm,
+    string CourseCode,
+    string CourseName,
+    decimal Credits,
+    decimal? Score,
+    decimal? GradePoint,
+    string ExamStatus);
+
+public sealed record GeneratedOfficialDocument(
+    byte[] Content,
+    string Sha256);

src/Jiaowu.Api/Infrastructure/Operations/DatabaseBackupService.cs

@@ -0,0 +1,584 @@
+using System.Diagnostics;
+using System.Security.Cryptography;
+using System.Text.Json;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.Data.Sqlite;
+using MySql.Data.MySqlClient;
+
+namespace Jiaowu.Api.Infrastructure.Operations;
+
+public sealed record BackupArtifact(
+    string Id,
+    string FileName,
+    string Provider,
+    DateTime CreatedAt,
+    long SizeBytes,
+    string Sha256,
+    string? Note,
+    DateTime? LastDrillAt,
+    bool? LastDrillSucceeded,
+    string? LastDrillDetail,
+    long? LastDrillDurationMilliseconds);
+
+public sealed record RestoreDrillResult(
+    string BackupId,
+    bool Succeeded,
+    DateTime CompletedAt,
+    string Detail,
+    long DurationMilliseconds,
+    int? TableCount);
+
+public sealed class DatabaseBackupService(
+    DatabaseOptions databaseOptions,
+    OperationsOptions options,
+    IConfiguration configuration,
+    IHostEnvironment environment,
+    ILogger<DatabaseBackupService> logger)
+{
+    private static readonly JsonSerializerOptions JsonOptions = new(JsonSerializerDefaults.Web)
+    {
+        WriteIndented = true
+    };
+
+    private readonly SemaphoreSlim operationLock = new(1, 1);
+    private readonly string backupDirectory = ResolveBackupDirectory(
+        options.BackupDirectory,
+        environment.ContentRootPath);
+
+    public async Task<IReadOnlyCollection<BackupArtifact>> ListAsync(
+        CancellationToken cancellationToken)
+    {
+        Directory.CreateDirectory(backupDirectory);
+        var items = new List<BackupArtifact>();
+        foreach (var metadataPath in Directory.EnumerateFiles(
+                     backupDirectory,
+                     "*.metadata.json",
+                     SearchOption.TopDirectoryOnly))
+        {
+            cancellationToken.ThrowIfCancellationRequested();
+            try
+            {
+                await using var stream = File.OpenRead(metadataPath);
+                var artifact = await JsonSerializer.DeserializeAsync<BackupArtifact>(
+                    stream,
+                    JsonOptions,
+                    cancellationToken);
+                if (artifact is not null &&
+                    File.Exists(Path.Combine(backupDirectory, artifact.FileName)))
+                {
+                    items.Add(artifact);
+                }
+            }
+            catch (Exception exception) when (
+                exception is IOException or UnauthorizedAccessException or JsonException)
+            {
+                logger.LogWarning(
+                    exception,
+                    "Unable to read backup metadata {MetadataFile}.",
+                    Path.GetFileName(metadataPath));
+            }
+        }
+
+        return items
+            .OrderByDescending(x => x.CreatedAt)
+            .ToArray();
+    }
+
+    public async Task<BackupArtifact> CreateAsync(
+        string? note,
+        CancellationToken cancellationToken)
+    {
+        await operationLock.WaitAsync(cancellationToken);
+        try
+        {
+            Directory.CreateDirectory(backupDirectory);
+            var createdAt = DateTime.UtcNow;
+            var id = $"{createdAt:yyyyMMddHHmmss}-{Guid.NewGuid():N}"[..29];
+            var provider = NormalizeProvider(databaseOptions.Provider);
+            var extension = provider == "SQLite" ? ".sqlite" : ".sql";
+            var fileName = $"jiaowu-{id}{extension}";
+            var backupPath = Path.Combine(backupDirectory, fileName);
+
+            try
+            {
+                if (provider == "SQLite")
+                    await CreateSqliteBackupAsync(backupPath, cancellationToken);
+                else
+                    await CreateMySqlBackupAsync(backupPath, cancellationToken);
+
+                var fileInfo = new FileInfo(backupPath);
+                var artifact = new BackupArtifact(
+                    id,
+                    fileName,
+                    provider,
+                    createdAt,
+                    fileInfo.Length,
+                    await ComputeHashAsync(backupPath, cancellationToken),
+                    NormalizeNote(note),
+                    null,
+                    null,
+                    null,
+                    null);
+                await WriteMetadataAsync(artifact, cancellationToken);
+                return artifact;
+            }
+            catch
+            {
+                if (File.Exists(backupPath))
+                    File.Delete(backupPath);
+                throw;
+            }
+        }
+        finally
+        {
+            operationLock.Release();
+        }
+    }
+
+    public async Task<RestoreDrillResult> RunRestoreDrillAsync(
+        string backupId,
+        CancellationToken cancellationToken)
+    {
+        await operationLock.WaitAsync(cancellationToken);
+        try
+        {
+            var artifact = (await ListAsync(cancellationToken))
+                .SingleOrDefault(x => x.Id.Equals(backupId, StringComparison.Ordinal));
+            if (artifact is null)
+                throw new FileNotFoundException("未找到指定备份。");
+
+            var backupPath = Path.Combine(backupDirectory, artifact.FileName);
+            var actualHash = await ComputeHashAsync(backupPath, cancellationToken);
+            if (!CryptographicOperations.FixedTimeEquals(
+                    Convert.FromHexString(artifact.Sha256),
+                    Convert.FromHexString(actualHash)))
+            {
+                var damaged = await CompleteDrillAsync(
+                    artifact,
+                    false,
+                    "备份文件校验和不一致，恢复演练已中止。",
+                    0,
+                    null,
+                    cancellationToken);
+                return damaged;
+            }
+
+            var stopwatch = Stopwatch.StartNew();
+            RestoreDrillResult result;
+            try
+            {
+                var tableCount = artifact.Provider == "SQLite"
+                    ? await DrillSqliteAsync(backupPath, cancellationToken)
+                    : await DrillMySqlAsync(backupPath, cancellationToken);
+                stopwatch.Stop();
+                result = await CompleteDrillAsync(
+                    artifact,
+                    true,
+                    $"已在隔离数据库完成恢复并通过完整性检查，共发现 {tableCount} 张业务表。",
+                    stopwatch.ElapsedMilliseconds,
+                    tableCount,
+                    cancellationToken);
+            }
+            catch (Exception exception) when (exception is not OperationCanceledException)
+            {
+                stopwatch.Stop();
+                logger.LogError(
+                    exception,
+                    "Restore drill failed for backup {BackupId}.",
+                    artifact.Id);
+                result = await CompleteDrillAsync(
+                    artifact,
+                    false,
+                    $"恢复演练失败：{SafeMessage(exception)}",
+                    stopwatch.ElapsedMilliseconds,
+                    null,
+                    cancellationToken);
+            }
+
+            return result;
+        }
+        finally
+        {
+            operationLock.Release();
+        }
+    }
+
+    private async Task CreateSqliteBackupAsync(
+        string backupPath,
+        CancellationToken cancellationToken)
+    {
+        var sourceBuilder = new SqliteConnectionStringBuilder(
+            configuration.GetConnectionString("SQLite")
+            ?? throw new InvalidOperationException("缺少 ConnectionStrings:SQLite。"));
+        if (!Path.IsPathRooted(sourceBuilder.DataSource))
+        {
+            sourceBuilder.DataSource = Path.GetFullPath(
+                sourceBuilder.DataSource,
+                environment.ContentRootPath);
+        }
+
+        var destinationBuilder = new SqliteConnectionStringBuilder
+        {
+            DataSource = backupPath,
+            Mode = SqliteOpenMode.ReadWriteCreate,
+            Pooling = false
+        };
+        await using var source = new SqliteConnection(sourceBuilder.ConnectionString);
+        await using var destination = new SqliteConnection(destinationBuilder.ConnectionString);
+        await source.OpenAsync(cancellationToken);
+        await destination.OpenAsync(cancellationToken);
+        source.BackupDatabase(destination);
+    }
+
+    private async Task CreateMySqlBackupAsync(
+        string backupPath,
+        CancellationToken cancellationToken)
+    {
+        var connection = GetMySqlConnectionBuilder();
+        var arguments = new List<string>
+        {
+            "--protocol=tcp",
+            $"--host={connection.Server}",
+            $"--port={connection.Port}",
+            $"--user={connection.UserID}",
+            "--single-transaction",
+            "--quick",
+            "--routines",
+            "--triggers",
+            "--events",
+            "--hex-blob",
+            "--default-character-set=utf8mb4"
+        };
+        arguments.AddRange(options.MySqlAdditionalArguments);
+        arguments.Add(connection.Database);
+
+        await using var output = new FileStream(
+            backupPath,
+            FileMode.CreateNew,
+            FileAccess.Write,
+            FileShare.None,
+            81920,
+            FileOptions.Asynchronous);
+        await RunToolAsync(
+            options.MySqlDumpPath,
+            arguments,
+            connection.Password,
+            standardInput: null,
+            standardOutput: output,
+            cancellationToken);
+    }
+
+    private static async Task<int> DrillSqliteAsync(
+        string backupPath,
+        CancellationToken cancellationToken)
+    {
+        var drillPath = Path.Combine(
+            Path.GetDirectoryName(backupPath)!,
+            $".restore-drill-{Guid.NewGuid():N}.sqlite");
+        try
+        {
+            var sourceBuilder = new SqliteConnectionStringBuilder
+            {
+                DataSource = backupPath,
+                Mode = SqliteOpenMode.ReadOnly,
+                Pooling = false
+            };
+            var drillBuilder = new SqliteConnectionStringBuilder
+            {
+                DataSource = drillPath,
+                Mode = SqliteOpenMode.ReadWriteCreate,
+                Pooling = false
+            };
+            await using var source = new SqliteConnection(sourceBuilder.ConnectionString);
+            await using var drill = new SqliteConnection(drillBuilder.ConnectionString);
+            await source.OpenAsync(cancellationToken);
+            await drill.OpenAsync(cancellationToken);
+            source.BackupDatabase(drill);
+
+            await using var integrity = drill.CreateCommand();
+            integrity.CommandText = "PRAGMA integrity_check;";
+            var integrityResult = Convert.ToString(
+                await integrity.ExecuteScalarAsync(cancellationToken));
+            if (!string.Equals(integrityResult, "ok", StringComparison.OrdinalIgnoreCase))
+                throw new InvalidDataException($"SQLite 完整性检查返回 {integrityResult ?? "空结果"}。");
+
+            await using var tables = drill.CreateCommand();
+            tables.CommandText =
+                "SELECT COUNT(*) FROM sqlite_master " +
+                "WHERE type = 'table' AND name NOT LIKE 'sqlite_%';";
+            return Convert.ToInt32(await tables.ExecuteScalarAsync(cancellationToken));
+        }
+        finally
+        {
+            if (File.Exists(drillPath))
+                File.Delete(drillPath);
+            if (File.Exists($"{drillPath}-shm"))
+                File.Delete($"{drillPath}-shm");
+            if (File.Exists($"{drillPath}-wal"))
+                File.Delete($"{drillPath}-wal");
+        }
+    }
+
+    private async Task<int> DrillMySqlAsync(
+        string backupPath,
+        CancellationToken cancellationToken)
+    {
+        var connection = GetMySqlConnectionBuilder();
+        var drillDatabase = $"jiaowu_restore_drill_{DateTime.UtcNow:yyyyMMddHHmmss}_" +
+                            Guid.NewGuid().ToString("N")[..8];
+        var adminBuilder = new MySqlConnectionStringBuilder(connection.ConnectionString)
+        {
+            Database = ""
+        };
+
+        await using var admin = new MySqlConnection(adminBuilder.ConnectionString);
+        await admin.OpenAsync(cancellationToken);
+        try
+        {
+            await using (var create = admin.CreateCommand())
+            {
+                create.CommandText =
+                    $"CREATE DATABASE `{drillDatabase}` CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;";
+                await create.ExecuteNonQueryAsync(cancellationToken);
+            }
+
+            var arguments = new List<string>
+            {
+                "--protocol=tcp",
+                $"--host={connection.Server}",
+                $"--port={connection.Port}",
+                $"--user={connection.UserID}",
+                "--default-character-set=utf8mb4"
+            };
+            arguments.AddRange(options.MySqlAdditionalArguments);
+            arguments.Add($"--database={drillDatabase}");
+            await using (var input = new FileStream(
+                             backupPath,
+                             FileMode.Open,
+                             FileAccess.Read,
+                             FileShare.Read,
+                             81920,
+                             FileOptions.Asynchronous))
+            {
+                await RunToolAsync(
+                    options.MySqlClientPath,
+                    arguments,
+                    connection.Password,
+                    input,
+                    standardOutput: null,
+                    cancellationToken);
+            }
+
+            await using var count = admin.CreateCommand();
+            count.CommandText =
+                "SELECT COUNT(*) FROM information_schema.tables " +
+                "WHERE table_schema = @schema AND table_type = 'BASE TABLE';";
+            count.Parameters.AddWithValue("@schema", drillDatabase);
+            return Convert.ToInt32(await count.ExecuteScalarAsync(cancellationToken));
+        }
+        finally
+        {
+            try
+            {
+                await using var drop = admin.CreateCommand();
+                drop.CommandText = $"DROP DATABASE IF EXISTS `{drillDatabase}`;";
+                await drop.ExecuteNonQueryAsync(CancellationToken.None);
+            }
+            catch (Exception exception)
+            {
+                logger.LogCritical(
+                    exception,
+                    "Unable to remove isolated restore drill database {DatabaseName}.",
+                    drillDatabase);
+            }
+        }
+    }
+
+    private async Task RunToolAsync(
+        string executable,
+        IReadOnlyCollection<string> arguments,
+        string password,
+        Stream? standardInput,
+        Stream? standardOutput,
+        CancellationToken cancellationToken)
+    {
+        var startInfo = new ProcessStartInfo
+        {
+            FileName = executable,
+            UseShellExecute = false,
+            RedirectStandardError = true,
+            RedirectStandardInput = standardInput is not null,
+            RedirectStandardOutput = standardOutput is not null,
+            CreateNoWindow = true
+        };
+        foreach (var argument in arguments)
+            startInfo.ArgumentList.Add(argument);
+        if (!string.IsNullOrEmpty(password))
+            startInfo.Environment["MYSQL_PWD"] = password;
+
+        using var process = Process.Start(startInfo)
+            ?? throw new InvalidOperationException($"无法启动数据库工具 {executable}。");
+        using var timeout = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+        timeout.CancelAfter(TimeSpan.FromMinutes(options.ToolTimeoutMinutes));
+        var errorTask = process.StandardError.ReadToEndAsync(timeout.Token);
+        var inputTask = standardInput is null
+            ? Task.CompletedTask
+            : CopyInputAsync(standardInput, process.StandardInput.BaseStream, timeout.Token);
+        var outputTask = standardOutput is null
+            ? Task.CompletedTask
+            : process.StandardOutput.BaseStream.CopyToAsync(
+                standardOutput,
+                timeout.Token);
+
+        try
+        {
+            await Task.WhenAll(
+                process.WaitForExitAsync(timeout.Token),
+                inputTask,
+                outputTask);
+        }
+        catch (OperationCanceledException)
+        {
+            if (!process.HasExited)
+                process.Kill(entireProcessTree: true);
+            throw;
+        }
+
+        var error = await errorTask;
+        if (process.ExitCode != 0)
+            throw new InvalidOperationException(
+                $"数据库工具执行失败（退出码 {process.ExitCode}）：{TrimToolError(error)}");
+    }
+
+    private static async Task CopyInputAsync(
+        Stream input,
+        Stream processInput,
+        CancellationToken cancellationToken)
+    {
+        await input.CopyToAsync(processInput, cancellationToken);
+        await processInput.FlushAsync(cancellationToken);
+        processInput.Close();
+    }
+
+    private MySqlConnectionStringBuilder GetMySqlConnectionBuilder()
+    {
+        var value = configuration.GetConnectionString("OperationsMySql");
+        if (string.IsNullOrWhiteSpace(value))
+        {
+            throw new InvalidOperationException(
+                "MySQL 备份与恢复演练必须配置独立的 " +
+                "ConnectionStrings:OperationsMySql 运维账号，不能复用日常业务账号。");
+        }
+        var builder = new MySqlConnectionStringBuilder(value);
+        if (string.IsNullOrWhiteSpace(builder.Database))
+            throw new InvalidOperationException(
+                "OperationsMySql 连接字符串未指定业务数据库名称。");
+        return builder;
+    }
+
+    private async Task<RestoreDrillResult> CompleteDrillAsync(
+        BackupArtifact artifact,
+        bool succeeded,
+        string detail,
+        long durationMilliseconds,
+        int? tableCount,
+        CancellationToken cancellationToken)
+    {
+        var completedAt = DateTime.UtcNow;
+        var updated = artifact with
+        {
+            LastDrillAt = completedAt,
+            LastDrillSucceeded = succeeded,
+            LastDrillDetail = detail,
+            LastDrillDurationMilliseconds = durationMilliseconds
+        };
+        await WriteMetadataAsync(updated, cancellationToken);
+        return new RestoreDrillResult(
+            artifact.Id,
+            succeeded,
+            completedAt,
+            detail,
+            durationMilliseconds,
+            tableCount);
+    }
+
+    private async Task WriteMetadataAsync(
+        BackupArtifact artifact,
+        CancellationToken cancellationToken)
+    {
+        var metadataPath = Path.Combine(
+            backupDirectory,
+            $"{artifact.Id}.metadata.json");
+        var temporaryPath = $"{metadataPath}.{Guid.NewGuid():N}.tmp";
+        try
+        {
+            await using (var stream = new FileStream(
+                             temporaryPath,
+                             FileMode.CreateNew,
+                             FileAccess.Write,
+                             FileShare.None,
+                             16384,
+                             FileOptions.Asynchronous))
+            {
+                await JsonSerializer.SerializeAsync(
+                    stream,
+                    artifact,
+                    JsonOptions,
+                    cancellationToken);
+            }
+            File.Move(temporaryPath, metadataPath, overwrite: true);
+        }
+        finally
+        {
+            if (File.Exists(temporaryPath))
+                File.Delete(temporaryPath);
+        }
+    }
+
+    private static async Task<string> ComputeHashAsync(
+        string path,
+        CancellationToken cancellationToken)
+    {
+        await using var stream = File.OpenRead(path);
+        return Convert.ToHexString(
+            await SHA256.HashDataAsync(stream, cancellationToken));
+    }
+
+    private static string ResolveBackupDirectory(
+        string configuredPath,
+        string contentRoot)
+    {
+        if (string.IsNullOrWhiteSpace(configuredPath))
+            throw new InvalidOperationException("Operations:BackupDirectory 不能为空。");
+        return Path.IsPathRooted(configuredPath)
+            ? Path.GetFullPath(configuredPath)
+            : Path.GetFullPath(configuredPath, contentRoot);
+    }
+
+    private static string NormalizeProvider(string provider) =>
+        provider.Equals("SQLite", StringComparison.OrdinalIgnoreCase)
+            ? "SQLite"
+            : provider.Equals("MySql", StringComparison.OrdinalIgnoreCase)
+                ? "MySql"
+                : throw new InvalidOperationException($"不支持数据库 Provider '{provider}'。");
+
+    private static string? NormalizeNote(string? note)
+    {
+        if (string.IsNullOrWhiteSpace(note)) return null;
+        var trimmed = note.Trim();
+        return trimmed.Length <= 200 ? trimmed : trimmed[..200];
+    }
+
+    private static string SafeMessage(Exception exception)
+    {
+        var message = exception.GetBaseException().Message;
+        return message.Length <= 500 ? message : message[..500];
+    }
+
+    private static string TrimToolError(string error)
+    {
+        var trimmed = error.Trim();
+        if (trimmed.Length == 0) return "未返回错误详情。";
+        return trimmed.Length <= 500 ? trimmed : trimmed[..500];
+    }
+}

src/Jiaowu.Api/Infrastructure/Operations/OperationalHealthService.cs

@@ -0,0 +1,200 @@
+using System.Diagnostics;
+using Jiaowu.Api.Infrastructure.BackgroundJobs;
+using Jiaowu.Api.Infrastructure.Caching;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Caching.Distributed;
+
+namespace Jiaowu.Api.Infrastructure.Operations;
+
+public sealed record OperationalComponentHealth(
+    string Key,
+    string Label,
+    string Status,
+    string Backend,
+    long? LatencyMilliseconds,
+    string Detail);
+
+public sealed record OperationalHealthSnapshot(
+    DateTime CheckedAt,
+    string OverallStatus,
+    IReadOnlyCollection<OperationalComponentHealth> Components,
+    BackgroundJobBacklogSnapshot? Backlog);
+
+public sealed class OperationalHealthService(
+    AppDbContext db,
+    IServiceProvider services,
+    IBackgroundJobTransport transport,
+    BackgroundJobMonitoringService monitoring,
+    DatabaseOptions databaseOptions,
+    AppCacheOptions cacheOptions,
+    IConfiguration configuration)
+{
+    public async Task<OperationalHealthSnapshot> CheckAsync(
+        CancellationToken cancellationToken)
+    {
+        var database = await CheckDatabaseAsync(cancellationToken);
+        var cache = await CheckCacheAsync(cancellationToken);
+        var (messaging, backlog) = await CheckMessagingAsync(cancellationToken);
+        var components = new[] { database, cache, messaging };
+        var overall = components.Any(x => x.Status == "unhealthy")
+            ? "unhealthy"
+            : components.Any(x => x.Status == "warning")
+                ? "warning"
+                : "healthy";
+        return new OperationalHealthSnapshot(
+            DateTime.UtcNow,
+            overall,
+            components,
+            backlog);
+    }
+
+    private async Task<OperationalComponentHealth> CheckDatabaseAsync(
+        CancellationToken cancellationToken)
+    {
+        var stopwatch = Stopwatch.StartNew();
+        try
+        {
+            var canConnect = await db.Database.CanConnectAsync(cancellationToken);
+            stopwatch.Stop();
+            return canConnect
+                ? new OperationalComponentHealth(
+                    "database",
+                    "数据库",
+                    "healthy",
+                    databaseOptions.Provider,
+                    stopwatch.ElapsedMilliseconds,
+                    "连接与基础查询正常。")
+                : new OperationalComponentHealth(
+                    "database",
+                    "数据库",
+                    "unhealthy",
+                    databaseOptions.Provider,
+                    stopwatch.ElapsedMilliseconds,
+                    "无法建立数据库连接。");
+        }
+        catch (Exception exception) when (exception is not OperationCanceledException)
+        {
+            stopwatch.Stop();
+            return new OperationalComponentHealth(
+                "database",
+                "数据库",
+                "unhealthy",
+                databaseOptions.Provider,
+                stopwatch.ElapsedMilliseconds,
+                SafeMessage(exception));
+        }
+    }
+
+    private async Task<OperationalComponentHealth> CheckCacheAsync(
+        CancellationToken cancellationToken)
+    {
+        if (!cacheOptions.Enabled)
+        {
+            return new OperationalComponentHealth(
+                "cache",
+                "缓存",
+                "warning",
+                "disabled",
+                null,
+                "缓存已通过配置关闭，所有查询将直接访问数据源。");
+        }
+
+        var hasRedisConfiguration = !string.IsNullOrWhiteSpace(
+            configuration.GetConnectionString("Redis"));
+        var distributedCache = services.GetService<IDistributedCache>();
+        if (!hasRedisConfiguration || distributedCache is null)
+        {
+            return new OperationalComponentHealth(
+                "cache",
+                "缓存",
+                "healthy",
+                "memory",
+                null,
+                "使用进程内混合缓存；服务重启后缓存会自然重建。");
+        }
+
+        var stopwatch = Stopwatch.StartNew();
+        try
+        {
+            await distributedCache.GetAsync(
+                "jiaowu:operations:health-probe",
+                cancellationToken);
+            stopwatch.Stop();
+            return new OperationalComponentHealth(
+                "cache",
+                "缓存",
+                "healthy",
+                "redis",
+                stopwatch.ElapsedMilliseconds,
+                "Redis 连接与读取探针正常。");
+        }
+        catch (Exception exception) when (exception is not OperationCanceledException)
+        {
+            stopwatch.Stop();
+            return new OperationalComponentHealth(
+                "cache",
+                "缓存",
+                "unhealthy",
+                "redis",
+                stopwatch.ElapsedMilliseconds,
+                SafeMessage(exception));
+        }
+    }
+
+    private async Task<(OperationalComponentHealth Component,
+        BackgroundJobBacklogSnapshot? Backlog)> CheckMessagingAsync(
+        CancellationToken cancellationToken)
+    {
+        var stopwatch = Stopwatch.StartNew();
+        BackgroundJobBacklogSnapshot? backlog = null;
+        try
+        {
+            var healthy = await transport.CheckHealthAsync(cancellationToken);
+            backlog = await monitoring.GetSnapshotAsync(cancellationToken);
+            stopwatch.Stop();
+            var stuck = backlog.ExpiredLeases > 0 ||
+                        backlog.OldestUnfinishedAgeSeconds > 1800;
+            var status = !healthy
+                ? "unhealthy"
+                : stuck
+                    ? "warning"
+                    : "healthy";
+            var detail = !healthy
+                ? "后台任务传输不可用。"
+                : stuck
+                    ? $"发现 {backlog.ExpiredLeases} 个过期租约，最早未完成任务已等待 " +
+                      $"{Math.Round(backlog.OldestUnfinishedAgeSeconds ?? 0)} 秒。"
+                    : $"待发布 {backlog.Pending + backlog.Publishing}，" +
+                      $"待处理 {backlog.Published + backlog.Processing}。";
+            return (
+                new OperationalComponentHealth(
+                    "messaging",
+                    "后台任务通道",
+                    status,
+                    transport.IsDurable ? "rabbitmq" : "memory",
+                    stopwatch.ElapsedMilliseconds,
+                    detail),
+                backlog);
+        }
+        catch (Exception exception) when (exception is not OperationCanceledException)
+        {
+            stopwatch.Stop();
+            return (
+                new OperationalComponentHealth(
+                    "messaging",
+                    "后台任务通道",
+                    "unhealthy",
+                    transport.IsDurable ? "rabbitmq" : "memory",
+                    stopwatch.ElapsedMilliseconds,
+                    SafeMessage(exception)),
+                backlog);
+        }
+    }
+
+    private static string SafeMessage(Exception exception)
+    {
+        var message = exception.GetBaseException().Message;
+        return message.Length <= 300 ? message : message[..300];
+    }
+}

src/Jiaowu.Api/Infrastructure/Operations/OperationsOptions.cs

@@ -0,0 +1,13 @@
+namespace Jiaowu.Api.Infrastructure.Operations;
+
+public sealed class OperationsOptions
+{
+    public const string SectionName = "Operations";
+
+    public string BackupDirectory { get; set; } = "data/backups";
+    public int BackupWarningHours { get; set; } = 24;
+    public int ToolTimeoutMinutes { get; set; } = 30;
+    public string MySqlDumpPath { get; set; } = "mysqldump";
+    public string MySqlClientPath { get; set; } = "mysql";
+    public string[] MySqlAdditionalArguments { get; set; } = [];
+}

src/Jiaowu.Api/Infrastructure/Persistence/AppDbContext.cs

@@ -22,6 +22,7 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
     public DbSet<Student> Students => Set<Student>();
     public DbSet<CourseCategory> CourseCategories => Set<CourseCategory>();
     public DbSet<Course> Courses => Set<Course>();
+    public DbSet<CoursePrerequisite> CoursePrerequisites => Set<CoursePrerequisite>();
     public DbSet<CurriculumPlan> CurriculumPlans => Set<CurriculumPlan>();
     public DbSet<CurriculumModule> CurriculumModules => Set<CurriculumModule>();
     public DbSet<CurriculumCourse> CurriculumCourses => Set<CurriculumCourse>();
@@ -41,8 +42,23 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
         Set<AutomaticScheduleJob>();
     public DbSet<SchedulePublishJob> SchedulePublishJobs =>
         Set<SchedulePublishJob>();
+    public DbSet<ClassroomReservation> ClassroomReservations =>
+        Set<ClassroomReservation>();
+    public DbSet<ExperimentProject> ExperimentProjects => Set<ExperimentProject>();
+    public DbSet<ExperimentSession> ExperimentSessions => Set<ExperimentSession>();
+    public DbSet<ExperimentBooking> ExperimentBookings => Set<ExperimentBooking>();
+    public DbSet<ExperimentGradeSheet> ExperimentGradeSheets =>
+        Set<ExperimentGradeSheet>();
+    public DbSet<ExperimentGradeItem> ExperimentGradeItems =>
+        Set<ExperimentGradeItem>();
+    public DbSet<ExperimentGradeRecord> ExperimentGradeRecords =>
+        Set<ExperimentGradeRecord>();
+    public DbSet<ExperimentGradeItemScore> ExperimentGradeItemScores =>
+        Set<ExperimentGradeItemScore>();
     public DbSet<CourseSelectionRound> CourseSelectionRounds =>
         Set<CourseSelectionRound>();
+    public DbSet<CourseSelectionRoundGrade> CourseSelectionRoundGrades =>
+        Set<CourseSelectionRoundGrade>();
     public DbSet<CourseSelectionOffering> CourseSelectionOfferings =>
         Set<CourseSelectionOffering>();
     public DbSet<CourseEnrollment> CourseEnrollments => Set<CourseEnrollment>();
@@ -52,10 +68,23 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
     public DbSet<GradeItemScore> GradeItemScores => Set<GradeItemScore>();
     public DbSet<AttendanceSheet> AttendanceSheets => Set<AttendanceSheet>();
     public DbSet<AttendanceRecord> AttendanceRecords => Set<AttendanceRecord>();
+    public DbSet<AttendanceCheckInAttempt> AttendanceCheckInAttempts =>
+        Set<AttendanceCheckInAttempt>();
     public DbSet<ExamPlan> ExamPlans => Set<ExamPlan>();
+    public DbSet<ExamArrangementJob> ExamArrangementJobs =>
+        Set<ExamArrangementJob>();
+    public DbSet<ExamSignInExportJob> ExamSignInExportJobs =>
+        Set<ExamSignInExportJob>();
+    public DbSet<ExamPublishJob> ExamPublishJobs =>
+        Set<ExamPublishJob>();
     public DbSet<ExamSession> ExamSessions => Set<ExamSession>();
     public DbSet<ExamSessionInvigilator> ExamSessionInvigilators =>
         Set<ExamSessionInvigilator>();
+    public DbSet<ExamRoomAssignment> ExamRooms => Set<ExamRoomAssignment>();
+    public DbSet<ExamRoomSession> ExamRoomSessions => Set<ExamRoomSession>();
+    public DbSet<ExamSeatAssignment> ExamSeats => Set<ExamSeatAssignment>();
+    public DbSet<ExamRoomInvigilator> ExamRoomInvigilators =>
+        Set<ExamRoomInvigilator>();
     public DbSet<MakeupExamPlan> MakeupExamPlans => Set<MakeupExamPlan>();
     public DbSet<MakeupExamSession> MakeupExamSessions => Set<MakeupExamSession>();
     public DbSet<MakeupExamSessionInvigilator> MakeupExamSessionInvigilators =>
@@ -75,6 +104,7 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
     public DbSet<EvaluationRecord> EvaluationRecords => Set<EvaluationRecord>();
     public DbSet<EvaluationScore> EvaluationScores => Set<EvaluationScore>();
     public DbSet<Notification> Notifications => Set<Notification>();
+    public DbSet<MessageDispatch> MessageDispatches => Set<MessageDispatch>();
     public DbSet<StudentStatusChange> StudentStatusChanges =>
         Set<StudentStatusChange>();
     public DbSet<GraduationAuditBatch> GraduationAuditBatches =>
@@ -89,7 +119,14 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
         Set<GraduationClearanceItem>();
     public DbSet<GraduationClearanceRecord> GraduationClearanceRecords =>
         Set<GraduationClearanceRecord>();
+    public DbSet<OfficialDocument> OfficialDocuments => Set<OfficialDocument>();
+    public DbSet<OfficialDocumentDownload> OfficialDocumentDownloads =>
+        Set<OfficialDocumentDownload>();
     public DbSet<AuditLog> AuditLogs => Set<AuditLog>();
+    public DbSet<BackgroundJobOutboxMessage> BackgroundJobOutboxMessages =>
+        Set<BackgroundJobOutboxMessage>();
+    public DbSet<AppUpdateRelease> AppUpdateReleases =>
+        Set<AppUpdateRelease>();
 
     protected override void ConfigureConventions(
         ModelConfigurationBuilder configurationBuilder)
@@ -101,6 +138,12 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
         configurationBuilder.Properties<DateOnly>()
             .HaveConversion<DateOnlyDateTimeConverter>()
             .HaveColumnType("date");
+
+        // Connector/NET returns MySQL TIME values as TimeSpan. Convert at the
+        // provider boundary so schedule time slots can still use TimeOnly.
+        configurationBuilder.Properties<TimeOnly>()
+            .HaveConversion<TimeOnlyTimeSpanConverter>()
+            .HaveColumnType("time");
     }
 
     protected override void OnModelCreating(ModelBuilder builder)
@@ -111,6 +154,7 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
         {
             entity.Property(x => x.DisplayName).HasMaxLength(50);
             entity.Property(x => x.StaffNumber).HasMaxLength(30);
+            entity.Property(x => x.CalendarSubscriptionStamp).HasMaxLength(64);
             entity.HasIndex(x => x.StaffNumber);
         });
 
@@ -230,6 +274,20 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
                 .OnDelete(DeleteBehavior.Restrict);
         });
 
+        builder.Entity<CoursePrerequisite>(entity =>
+        {
+            entity.HasIndex(x => new { x.CourseId, x.PrerequisiteCourseId })
+                .IsUnique();
+            entity.HasOne(x => x.Course)
+                .WithMany(x => x.Prerequisites)
+                .HasForeignKey(x => x.CourseId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.PrerequisiteCourse)
+                .WithMany(x => x.RequiredByCourses)
+                .HasForeignKey(x => x.PrerequisiteCourseId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
+
         builder.Entity<CurriculumPlan>(entity =>
         {
             entity.Property(x => x.Name).HasMaxLength(120);
@@ -358,6 +416,8 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
 
         builder.Entity<ScheduleEntry>(entity =>
         {
+            entity.Property(x => x.Kind)
+                .HasDefaultValue(ScheduleEntryKind.Lecture);
             entity.Property(x => x.Notes).HasMaxLength(500);
             entity.HasIndex(x => new
             {
@@ -459,6 +519,176 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
                 .OnDelete(DeleteBehavior.SetNull);
         });
 
+        builder.Entity<ClassroomReservation>(entity =>
+        {
+            entity.Property(x => x.ApplicantName).HasMaxLength(50);
+            entity.Property(x => x.Purpose).HasMaxLength(200);
+            entity.Property(x => x.ContactPhone).HasMaxLength(30);
+            entity.Property(x => x.Notes).HasMaxLength(500);
+            entity.Property(x => x.ReviewComment).HasMaxLength(500);
+            entity.HasIndex(x => new { x.ApplicantUserId, x.Status, x.CreatedAt });
+            entity.HasIndex(x => new
+            {
+                x.ApplicantCollegeId,
+                x.Status,
+                x.ReservationDate
+            });
+            entity.HasIndex(x => new
+            {
+                x.ClassroomId,
+                x.ReservationDate,
+                x.Status,
+                x.StartPeriod
+            });
+            entity.HasOne(x => x.ApplicantUser)
+                .WithMany()
+                .HasForeignKey(x => x.ApplicantUserId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.ApplicantCollege)
+                .WithMany()
+                .HasForeignKey(x => x.ApplicantCollegeId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.AcademicTerm)
+                .WithMany()
+                .HasForeignKey(x => x.AcademicTermId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.Classroom)
+                .WithMany()
+                .HasForeignKey(x => x.ClassroomId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.ReviewedByUser)
+                .WithMany()
+                .HasForeignKey(x => x.ReviewedByUserId)
+                .OnDelete(DeleteBehavior.SetNull);
+        });
+
+        builder.Entity<ExperimentProject>(entity =>
+        {
+            entity.Property(x => x.Code).HasMaxLength(40);
+            entity.Property(x => x.Name).HasMaxLength(120);
+            entity.Property(x => x.Description).HasMaxLength(1000);
+            entity.Property(x => x.Requirements).HasMaxLength(1000);
+            entity.HasIndex(x => new { x.TeachingTaskId, x.Code }).IsUnique();
+            entity.HasIndex(x => new { x.Status, x.StartDate, x.EndDate });
+            entity.HasOne(x => x.TeachingTask).WithMany()
+                .HasForeignKey(x => x.TeachingTaskId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
+
+        builder.Entity<ExperimentSession>(entity =>
+        {
+            entity.Property(x => x.Notes).HasMaxLength(500);
+            entity.HasIndex(x => new
+            {
+                x.ExperimentProjectId,
+                x.SessionDate,
+                x.StartPeriod
+            });
+            entity.HasIndex(x => new
+            {
+                x.ClassroomId,
+                x.SessionDate,
+                x.Status,
+                x.StartPeriod
+            });
+            entity.HasOne(x => x.ExperimentProject).WithMany(x => x.Sessions)
+                .HasForeignKey(x => x.ExperimentProjectId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.Classroom).WithMany()
+                .HasForeignKey(x => x.ClassroomId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
+
+        builder.Entity<ExperimentBooking>(entity =>
+        {
+            entity.HasIndex(x => new { x.ExperimentProjectId, x.StudentId })
+                .IsUnique();
+            entity.HasIndex(x => new
+            {
+                x.ExperimentSessionId,
+                x.Status,
+                x.BookedAt
+            });
+            entity.HasOne(x => x.ExperimentProject).WithMany(x => x.Bookings)
+                .HasForeignKey(x => x.ExperimentProjectId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.ExperimentSession).WithMany(x => x.Bookings)
+                .HasForeignKey(x => x.ExperimentSessionId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.Student).WithMany()
+                .HasForeignKey(x => x.StudentId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
+
+        builder.Entity<ExperimentGradeSheet>(entity =>
+        {
+            entity.Property(x => x.ContributionWeight).HasPrecision(5, 1);
+            entity.Property(x => x.PassScore).HasPrecision(5, 1);
+            entity.Property(x => x.ReviewComment).HasMaxLength(500);
+            entity.HasIndex(x => x.ExperimentProjectId).IsUnique();
+            entity.HasOne(x => x.ExperimentProject)
+                .WithOne(x => x.GradeSheet)
+                .HasForeignKey<ExperimentGradeSheet>(
+                    x => x.ExperimentProjectId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
+        builder.Entity<ExperimentGradeItem>(entity =>
+        {
+            entity.Property(x => x.Name).HasMaxLength(60);
+            entity.Property(x => x.Weight).HasPrecision(5, 1);
+            entity.HasIndex(x => new
+            {
+                x.ExperimentGradeSheetId,
+                x.SortOrder
+            });
+            entity.HasOne(x => x.ExperimentGradeSheet)
+                .WithMany(x => x.Items)
+                .HasForeignKey(x => x.ExperimentGradeSheetId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
+        builder.Entity<ExperimentGradeRecord>(entity =>
+        {
+            entity.Property(x => x.TotalScore).HasPrecision(5, 1);
+            entity.Property(x => x.SubmissionReference).HasMaxLength(500);
+            entity.Property(x => x.TeacherComment).HasMaxLength(500);
+            entity.HasIndex(x => new
+            {
+                x.ExperimentGradeSheetId,
+                x.StudentId
+            }).IsUnique();
+            entity.HasOne(x => x.ExperimentGradeSheet)
+                .WithMany(x => x.Records)
+                .HasForeignKey(x => x.ExperimentGradeSheetId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.Student).WithMany()
+                .HasForeignKey(x => x.StudentId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.ExperimentSession).WithMany()
+                .HasForeignKey(x => x.ExperimentSessionId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
+
+        builder.Entity<ExperimentGradeItemScore>(entity =>
+        {
+            entity.HasKey(x => new
+            {
+                x.ExperimentGradeRecordId,
+                x.ExperimentGradeItemId
+            });
+            entity.Property(x => x.Score).HasPrecision(5, 1);
+            entity.Property(x => x.Comment).HasMaxLength(300);
+            entity.HasOne(x => x.ExperimentGradeRecord)
+                .WithMany(x => x.ItemScores)
+                .HasForeignKey(x => x.ExperimentGradeRecordId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.ExperimentGradeItem)
+                .WithMany(x => x.Scores)
+                .HasForeignKey(x => x.ExperimentGradeItemId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
         builder.Entity<CourseSelectionRound>(entity =>
         {
             entity.Property(x => x.Name).HasMaxLength(120);
@@ -471,6 +701,17 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
                 .OnDelete(DeleteBehavior.Restrict);
         });
 
+        builder.Entity<CourseSelectionRoundGrade>(entity =>
+        {
+            entity.HasIndex(x => new { x.CourseSelectionRoundId, x.Grade })
+                .IsUnique();
+            entity.HasIndex(x => x.Grade);
+            entity.HasOne(x => x.CourseSelectionRound)
+                .WithMany(x => x.EligibleGrades)
+                .HasForeignKey(x => x.CourseSelectionRoundId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
         builder.Entity<CourseSelectionOffering>(entity =>
         {
             entity.Property(x => x.Notes).HasMaxLength(500);
@@ -494,6 +735,12 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
             entity.HasIndex(x => new { x.CourseSelectionOfferingId, x.StudentId })
                 .IsUnique();
             entity.HasIndex(x => new { x.StudentId, x.Status });
+            entity.HasIndex(x => new
+            {
+                x.CourseSelectionOfferingId,
+                x.Status,
+                x.WaitlistedAt
+            }).HasDatabaseName("IX_CE_Offering_Status_WaitlistedAt");
             entity.HasOne(x => x.CourseSelectionOffering)
                 .WithMany(x => x.Enrollments)
                 .HasForeignKey(x => x.CourseSelectionOfferingId)
@@ -521,6 +768,8 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
         {
             entity.Property(x => x.Name).HasMaxLength(60);
             entity.Property(x => x.Weight).HasPrecision(5, 1);
+            entity.Property(x => x.SourceType)
+                .HasDefaultValue(GradeItemSourceType.Manual);
             entity.HasIndex(x => new { x.GradeSheetId, x.SortOrder });
             entity.HasOne(x => x.GradeSheet)
                 .WithMany(x => x.Items)
@@ -595,6 +844,29 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
                 .OnDelete(DeleteBehavior.Restrict);
         });
 
+        builder.Entity<AttendanceCheckInAttempt>(entity =>
+        {
+            entity.Property(x => x.FailureCode).HasMaxLength(64);
+            entity.Property(x => x.DeviceIdentifierHash).HasMaxLength(64);
+            entity.Property(x => x.DevicePlatform).HasMaxLength(32);
+            entity.Property(x => x.IpAddress).HasMaxLength(64);
+            entity.Property(x => x.UserAgent).HasMaxLength(500);
+            entity.Property(x => x.RiskFlags).HasMaxLength(300);
+            entity.Property(x => x.Latitude).HasPrecision(10, 7);
+            entity.Property(x => x.Longitude).HasPrecision(10, 7);
+            entity.HasIndex(x => new { x.AttendanceSheetId, x.StudentId, x.CreatedAt });
+            entity.HasIndex(x => new { x.DeviceIdentifierHash, x.CreatedAt });
+            entity.HasIndex(x => new { x.IpAddress, x.CreatedAt });
+            entity.HasOne(x => x.AttendanceSheet)
+                .WithMany(x => x.CheckInAttempts)
+                .HasForeignKey(x => x.AttendanceSheetId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.Student)
+                .WithMany()
+                .HasForeignKey(x => x.StudentId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
+
         builder.Entity<ExamPlan>(entity =>
         {
             entity.Property(x => x.Name).HasMaxLength(120);
@@ -610,6 +882,7 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
             entity.HasIndex(x => x.TeachingTaskId);
             entity.HasIndex(x => new { x.ExamPlanId, x.ExamDate });
             entity.HasIndex(x => x.RequiredBuildingId);
+            entity.Property(x => x.RequiredBuildingIds).HasColumnType("longtext");
             entity.HasOne(x => x.ExamPlan).WithMany(x => x.Sessions)
                 .HasForeignKey(x => x.ExamPlanId).OnDelete(DeleteBehavior.Cascade);
             entity.HasOne(x => x.TeachingTask).WithMany()
@@ -627,6 +900,87 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
             entity.HasOne(x => x.Teacher).WithMany()
                 .HasForeignKey(x => x.TeacherId).OnDelete(DeleteBehavior.Restrict);
         });
+        builder.Entity<ExamRoomAssignment>(entity =>
+        {
+            entity.ToTable("ExamRooms");
+            entity.HasIndex(x => new { x.ExamPlanId, x.StartsAt })
+                .HasDatabaseName("IX_ExamRooms_Plan_Time");
+            entity.HasIndex(x => new
+                {
+                    x.ExamPlanId,
+                    x.ClassroomId,
+                    x.StartsAt
+                })
+                .HasDatabaseName("IX_ExamRooms_Plan_Room_Time");
+            entity.HasIndex(x => x.CourseId)
+                .HasDatabaseName("IX_ExamRooms_CourseId");
+            entity.HasOne(x => x.ExamPlan).WithMany(x => x.Rooms)
+                .HasForeignKey(x => x.ExamPlanId).OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.Course).WithMany()
+                .HasForeignKey(x => x.CourseId).OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.Classroom).WithMany()
+                .HasForeignKey(x => x.ClassroomId).OnDelete(DeleteBehavior.Restrict);
+        });
+        builder.Entity<ExamRoomSession>(entity =>
+        {
+            entity.ToTable("ExamRoomSessions");
+            entity.HasKey(x => new { x.ExamRoomId, x.ExamSessionId });
+            entity.HasIndex(x => x.ExamSessionId)
+                .HasDatabaseName("IX_ExamRoomSessions_SessionId");
+            entity.HasOne(x => x.ExamRoom).WithMany(x => x.SessionLinks)
+                .HasForeignKey(x => x.ExamRoomId).OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.ExamSession).WithMany(x => x.RoomLinks)
+                .HasForeignKey(x => x.ExamSessionId).OnDelete(DeleteBehavior.Restrict);
+        });
+        builder.Entity<ExamSeatAssignment>(entity =>
+        {
+            entity.ToTable("ExamSeats");
+            entity.HasKey(x => new { x.ExamRoomId, x.StudentId });
+            entity.HasIndex(x => new { x.ExamSessionId, x.StudentId })
+                .IsUnique()
+                .HasDatabaseName("UX_ExamSeats_Session_Student");
+            entity.HasIndex(x => x.StudentId)
+                .HasDatabaseName("IX_ExamSeats_StudentId");
+            entity.HasOne(x => x.ExamRoom).WithMany(x => x.Seats)
+                .HasForeignKey(x => x.ExamRoomId).OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.ExamSession).WithMany(x => x.SeatAssignments)
+                .HasForeignKey(x => x.ExamSessionId).OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.Student).WithMany()
+                .HasForeignKey(x => x.StudentId).OnDelete(DeleteBehavior.Restrict);
+        });
+        builder.Entity<ExamRoomInvigilator>(entity =>
+        {
+            entity.ToTable("ExamRoomInvigilators");
+            entity.HasKey(x => new { x.ExamRoomId, x.TeacherId });
+            entity.HasIndex(x => x.TeacherId)
+                .HasDatabaseName("IX_ExamRoomInvigilators_TeacherId");
+            entity.HasOne(x => x.ExamRoom).WithMany(x => x.Invigilators)
+                .HasForeignKey(x => x.ExamRoomId).OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.Teacher).WithMany()
+                .HasForeignKey(x => x.TeacherId).OnDelete(DeleteBehavior.Restrict);
+        });
+        builder.Entity<ExamArrangementJob>(entity =>
+        {
+            entity.Property(x => x.CurrentStep).HasMaxLength(200);
+            entity.Property(x => x.ResultMessage).HasMaxLength(2000);
+            entity.Property(x => x.ErrorMessage).HasMaxLength(2000);
+            entity.HasIndex(x => new { x.Kind, x.ActivePlanId })
+                .IsUnique()
+                .HasDatabaseName("UX_ExamArrangementJobs_Kind_ActivePlan");
+            entity.HasIndex(x => new { x.Kind, x.PlanId, x.CreatedAt })
+                .HasDatabaseName("IX_ExamArrangementJobs_Kind_Plan_CreatedAt");
+            entity.HasIndex(x => new { x.Status, x.CreatedAt });
+            entity.HasIndex(x => x.RequestedByUserId);
+        });
+        builder.Entity<ExamSignInExportJob>(entity =>
+        {
+            entity.Property(x => x.CurrentStep).HasMaxLength(200);
+            entity.Property(x => x.FileName).HasMaxLength(200);
+            entity.Property(x => x.ErrorMessage).HasMaxLength(2000);
+            entity.HasIndex(x => new { x.PlanId, x.CreatedAt });
+            entity.HasIndex(x => new { x.Status, x.CreatedAt });
+            entity.HasIndex(x => x.RequestedByUserId);
+        });
         builder.Entity<MakeupExamPlan>(entity =>
         {
             entity.Property(x => x.Name).HasMaxLength(120);
@@ -642,6 +996,7 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
             entity.HasIndex(x => x.TeachingTaskId);
             entity.HasIndex(x => new { x.MakeupExamPlanId, x.ExamDate });
             entity.HasIndex(x => x.RequiredBuildingId);
+            entity.Property(x => x.RequiredBuildingIds).HasColumnType("longtext");
             entity.HasOne(x => x.MakeupExamPlan).WithMany(x => x.Sessions)
                 .HasForeignKey(x => x.MakeupExamPlanId).OnDelete(DeleteBehavior.Cascade);
             entity.HasOne(x => x.TeachingTask).WithMany()
@@ -876,6 +1231,7 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
             entity.HasIndex(x => new { x.TeachingTaskId, x.Status });
             entity.HasIndex(x => x.ApplicantUserId);
             entity.HasIndex(x => new { x.Status, x.CreatedAt });
+            entity.HasIndex(x => new { x.SourceScheduleEntryId, x.SourceWeek });
             entity.HasOne(x => x.TeachingTask).WithMany()
                 .HasForeignKey(x => x.TeachingTaskId).OnDelete(DeleteBehavior.Restrict);
             entity.HasOne(x => x.Classroom).WithMany()
@@ -887,10 +1243,26 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
         builder.Entity<Notification>(entity =>
         {
             entity.Property(x => x.Title).HasMaxLength(200);
-            entity.Property(x => x.Content).HasMaxLength(1000);
+            entity.Property(x => x.Content).HasColumnType("longtext");
             entity.Property(x => x.LinkUrl).HasMaxLength(300);
             entity.HasIndex(x => new { x.UserId, x.IsRead });
+            entity.HasIndex(x => new { x.UserId, x.Category, x.CreatedAt });
+            entity.HasIndex(x => x.MessageDispatchId);
             entity.HasIndex(x => x.CreatedAt);
+            entity.HasOne(x => x.MessageDispatch)
+                .WithMany(x => x.Notifications)
+                .HasForeignKey(x => x.MessageDispatchId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
+        builder.Entity<MessageDispatch>(entity =>
+        {
+            entity.Property(x => x.SenderName).HasMaxLength(100);
+            entity.Property(x => x.Title).HasMaxLength(200);
+            entity.Property(x => x.Content).HasColumnType("longtext");
+            entity.Property(x => x.AudienceName).HasMaxLength(200);
+            entity.Property(x => x.LinkUrl).HasMaxLength(300);
+            entity.HasIndex(x => new { x.SenderUserId, x.CreatedAt });
         });
 
         builder.Entity<AuditLog>(entity =>
@@ -901,6 +1273,99 @@ public sealed class AppDbContext(DbContextOptions<AppDbContext> options)
             entity.Property(x => x.IpAddress).HasMaxLength(64);
             entity.HasIndex(x => x.CreatedAt);
         });
+
+        builder.Entity<BackgroundJobOutboxMessage>(entity =>
+        {
+            entity.Property(x => x.LastError).HasMaxLength(2000);
+            entity.HasIndex(x => new { x.JobKind, x.JobId }).IsUnique();
+            entity.HasIndex(x => new { x.State, x.CreatedAt });
+            entity.HasIndex(x => new { x.State, x.CompletedAt });
+            entity.HasIndex(x => x.LeaseExpiresAt);
+        });
+
+        builder.Entity<AppUpdateRelease>(entity =>
+        {
+            entity.Property(x => x.Platform)
+                .HasConversion<string>()
+                .HasMaxLength(20);
+            entity.Property(x => x.Channel)
+                .HasConversion<string>()
+                .HasMaxLength(20);
+            entity.Property(x => x.Status)
+                .HasConversion<string>()
+                .HasMaxLength(20);
+            entity.Property(x => x.Version).HasMaxLength(40);
+            entity.Property(x => x.NativeVersion).HasMaxLength(40);
+            entity.Property(x => x.ReleaseNotes).HasMaxLength(1000);
+            entity.Property(x => x.FileName).HasMaxLength(180);
+            entity.Property(x => x.Sha256).HasMaxLength(64);
+            entity.Property(x => x.BundleContent).HasColumnType("longblob");
+            entity.Property(x => x.CreatedByUserName).HasMaxLength(100);
+            entity.Property(x => x.PublishedByUserName).HasMaxLength(100);
+            entity.HasIndex(x => new
+            {
+                x.Platform,
+                x.Channel,
+                x.NativeVersion,
+                x.Version
+            }).IsUnique();
+            entity.HasIndex(x => new
+            {
+                x.Platform,
+                x.Channel,
+                x.NativeVersion,
+                x.Status
+            });
+            entity.HasIndex(x => x.CreatedAt);
+        });
+
+        builder.Entity<OfficialDocument>(entity =>
+        {
+            entity.Property(x => x.DocumentNumber).HasMaxLength(50);
+            entity.Property(x => x.VerificationCodeHash).HasMaxLength(64);
+            entity.Property(x => x.Purpose).HasMaxLength(200);
+            entity.Property(x => x.SnapshotJson).HasColumnType("longtext");
+            entity.Property(x => x.PdfContent).HasColumnType("longblob");
+            entity.Property(x => x.PdfSha256).HasMaxLength(64);
+            entity.Property(x => x.InvalidationReason).HasMaxLength(500);
+            entity.HasIndex(x => x.DocumentNumber).IsUnique();
+            entity.HasIndex(x => x.VerificationCodeHash).IsUnique();
+            entity.HasIndex(x => new { x.StudentId, x.IssuedAt });
+            entity.HasIndex(x => new { x.Status, x.IssuedAt });
+            entity.HasOne(x => x.Student)
+                .WithMany()
+                .HasForeignKey(x => x.StudentId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.IssuedByUser)
+                .WithMany()
+                .HasForeignKey(x => x.IssuedByUserId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(x => x.InvalidatedByUser)
+                .WithMany()
+                .HasForeignKey(x => x.InvalidatedByUserId)
+                .OnDelete(DeleteBehavior.Restrict);
+            entity.HasIndex(x => x.ReissuedFromDocumentId).IsUnique();
+            entity.HasOne(x => x.ReissuedFromDocument)
+                .WithMany()
+                .HasForeignKey(x => x.ReissuedFromDocumentId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
+
+        builder.Entity<OfficialDocumentDownload>(entity =>
+        {
+            entity.Property(x => x.IpAddress).HasMaxLength(64);
+            entity.Property(x => x.UserAgent).HasMaxLength(500);
+            entity.HasIndex(x => new { x.OfficialDocumentId, x.CreatedAt });
+            entity.HasIndex(x => new { x.DownloadedByUserId, x.CreatedAt });
+            entity.HasOne(x => x.OfficialDocument)
+                .WithMany(x => x.Downloads)
+                .HasForeignKey(x => x.OfficialDocumentId)
+                .OnDelete(DeleteBehavior.Cascade);
+            entity.HasOne(x => x.DownloadedByUser)
+                .WithMany()
+                .HasForeignKey(x => x.DownloadedByUserId)
+                .OnDelete(DeleteBehavior.Restrict);
+        });
     }
 
     public override Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
@@ -931,3 +1396,8 @@ public sealed class DateOnlyDateTimeConverter()
     : ValueConverter<DateOnly, DateTime>(
         date => date.ToDateTime(TimeOnly.MinValue),
         value => DateOnly.FromDateTime(value));
+
+public sealed class TimeOnlyTimeSpanConverter()
+    : ValueConverter<TimeOnly, TimeSpan>(
+        time => time.ToTimeSpan(),
+        value => TimeOnly.FromTimeSpan(value));

src/Jiaowu.Api/Infrastructure/Persistence/AppDbContextFactory.cs

@@ -12,7 +12,7 @@ public sealed class AppDbContextFactory : IDesignTimeDbContextFactory<AppDbConte
             ?? "Server=localhost;Port=3306;Database=jiaowu;User=__design_time__;Password=__not_used__;";
 
         var options = new DbContextOptionsBuilder<AppDbContext>()
-            .UseMySQL(connectionString)
+            .UseMySQL(MySqlConnectionStringPolicy.ForApplication(connectionString))
             .Options;
 
         return new AppDbContext(options);

src/Jiaowu.Api/Infrastructure/Persistence/DemoDataSeeder.cs

@@ -1,11 +1,13 @@
 using System.Data;
 using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
 using Microsoft.EntityFrameworkCore;
 
 namespace Jiaowu.Api.Infrastructure.Persistence;
 
 public sealed class DemoDataSeeder(
     AppDbContext db,
+    IAppCache cache,
     ILogger<DemoDataSeeder> logger)
 {
     // MySql.EntityFrameworkCore 10 cannot type-map parameterized primitive
@@ -47,6 +49,10 @@ public sealed class DemoDataSeeder(
             await LogSummaryAsync(cancellationToken);
             await transaction.CommitAsync(cancellationToken);
         });
+
+        await cache.RemoveByTagAsync(AppCacheTags.BaseData, cancellationToken);
+        await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
+        await cache.RemoveByTagAsync(AppCacheTags.Analytics, cancellationToken);
     }
 
     private async Task EnsureDatabaseIsEmptyAsync(CancellationToken cancellationToken)

src/Jiaowu.Api/Infrastructure/Persistence/Migrations/MySql/20260726094419_OfficialDocuments.cs

@@ -0,0 +1,156 @@
+using System;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql
+{
+    /// <inheritdoc />
+    public partial class OfficialDocuments : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "OfficialDocuments",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false),
+                    DocumentNumber = table.Column<string>(type: "varchar(50)", maxLength: 50, nullable: false),
+                    VerificationCodeHash = table.Column<string>(type: "varchar(64)", maxLength: 64, nullable: false),
+                    Type = table.Column<int>(type: "int", nullable: false),
+                    Status = table.Column<int>(type: "int", nullable: false),
+                    StudentId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    IssuedByUserId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    IssuedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false),
+                    Purpose = table.Column<string>(type: "varchar(200)", maxLength: 200, nullable: true),
+                    SnapshotJson = table.Column<string>(type: "longtext", nullable: false),
+                    PdfContent = table.Column<byte[]>(type: "longblob", nullable: false),
+                    PdfSha256 = table.Column<string>(type: "varchar(64)", maxLength: 64, nullable: false),
+                    InvalidatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: true),
+                    InvalidatedByUserId = table.Column<Guid>(type: "char(36)", nullable: true),
+                    InvalidationReason = table.Column<string>(type: "varchar(500)", maxLength: 500, nullable: true),
+                    ReissuedFromDocumentId = table.Column<Guid>(type: "char(36)", nullable: true),
+                    CreatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_OfficialDocuments", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_OfficialDocuments_AspNetUsers_InvalidatedByUserId",
+                        column: x => x.InvalidatedByUserId,
+                        principalTable: "AspNetUsers",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_OfficialDocuments_AspNetUsers_IssuedByUserId",
+                        column: x => x.IssuedByUserId,
+                        principalTable: "AspNetUsers",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_OfficialDocuments_OfficialDocuments_ReissuedFromDocumentId",
+                        column: x => x.ReissuedFromDocumentId,
+                        principalTable: "OfficialDocuments",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_OfficialDocuments_Students_StudentId",
+                        column: x => x.StudentId,
+                        principalTable: "Students",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                })
+                .Annotation("MySQL:Charset", "utf8mb4");
+
+            migrationBuilder.CreateTable(
+                name: "OfficialDocumentDownloads",
+                columns: table => new
+                {
+                    Id = table.Column<Guid>(type: "char(36)", nullable: false),
+                    OfficialDocumentId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    DownloadedByUserId = table.Column<Guid>(type: "char(36)", nullable: false),
+                    IpAddress = table.Column<string>(type: "varchar(64)", maxLength: 64, nullable: true),
+                    UserAgent = table.Column<string>(type: "varchar(500)", maxLength: 500, nullable: true),
+                    CreatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false),
+                    UpdatedAt = table.Column<DateTime>(type: "datetime(6)", nullable: false)
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("PK_OfficialDocumentDownloads", x => x.Id);
+                    table.ForeignKey(
+                        name: "FK_OfficialDocumentDownloads_AspNetUsers_DownloadedByUserId",
+                        column: x => x.DownloadedByUserId,
+                        principalTable: "AspNetUsers",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Restrict);
+                    table.ForeignKey(
+                        name: "FK_OfficialDocumentDownloads_OfficialDocuments_OfficialDocument~",
+                        column: x => x.OfficialDocumentId,
+                        principalTable: "OfficialDocuments",
+                        principalColumn: "Id",
+                        onDelete: ReferentialAction.Cascade);
+                })
+                .Annotation("MySQL:Charset", "utf8mb4");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_OfficialDocumentDownloads_DownloadedByUserId_CreatedAt",
+                table: "OfficialDocumentDownloads",
+                columns: new[] { "DownloadedByUserId", "CreatedAt" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_OfficialDocumentDownloads_OfficialDocumentId_CreatedAt",
+                table: "OfficialDocumentDownloads",
+                columns: new[] { "OfficialDocumentId", "CreatedAt" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_OfficialDocuments_DocumentNumber",
+                table: "OfficialDocuments",
+                column: "DocumentNumber",
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_OfficialDocuments_InvalidatedByUserId",
+                table: "OfficialDocuments",
+                column: "InvalidatedByUserId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_OfficialDocuments_IssuedByUserId",
+                table: "OfficialDocuments",
+                column: "IssuedByUserId");
+
+            migrationBuilder.CreateIndex(
+                name: "IX_OfficialDocuments_ReissuedFromDocumentId",
+                table: "OfficialDocuments",
+                column: "ReissuedFromDocumentId",
+                unique: true);
+
+            migrationBuilder.CreateIndex(
+                name: "IX_OfficialDocuments_Status_IssuedAt",
+                table: "OfficialDocuments",
+                columns: new[] { "Status", "IssuedAt" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_OfficialDocuments_StudentId_IssuedAt",
+                table: "OfficialDocuments",
+                columns: new[] { "StudentId", "IssuedAt" });
+
+            migrationBuilder.CreateIndex(
+                name: "IX_OfficialDocuments_VerificationCodeHash",
+                table: "OfficialDocuments",
+                column: "VerificationCodeHash",
+                unique: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(
+                name: "OfficialDocumentDownloads");
+
+            migrationBuilder.DropTable(
+                name: "OfficialDocuments");
+        }
+    }
+}

src/Jiaowu.Api/Infrastructure/Persistence/Migrations/MySql/20260726170000_CourseSelectionWaitlist.cs

@@ -0,0 +1,102 @@
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace Jiaowu.Api.Infrastructure.Persistence.Migrations.MySql;
+
+[DbContext(typeof(AppDbContext))]
+[Migration("20260726170000_CourseSelectionWaitlist")]
+public partial class CourseSelectionWaitlist : Migration
+{
+    protected override void Up(MigrationBuilder migrationBuilder)
+    {
+        migrationBuilder.Sql("""
+            SET @waitlisted_column_exists = (
+                SELECT COUNT(*)
+                FROM `INFORMATION_SCHEMA`.`COLUMNS`
+                WHERE `TABLE_SCHEMA` = DATABASE()
+                  AND `TABLE_NAME` = 'CourseEnrollments'
+                  AND `COLUMN_NAME` = 'WaitlistedAt'
+            );
+            """);
+        migrationBuilder.Sql("""
+            SET @add_waitlisted_column_sql = IF(
+                @waitlisted_column_exists = 0,
+                'ALTER TABLE `CourseEnrollments` ADD COLUMN `WaitlistedAt` datetime(6) NULL',
+                'SELECT 1'
+            );
+            """);
+        migrationBuilder.Sql(
+            "PREPARE add_waitlisted_column_stmt FROM @add_waitlisted_column_sql;");
+        migrationBuilder.Sql("EXECUTE add_waitlisted_column_stmt;");
+        migrationBuilder.Sql("DEALLOCATE PREPARE add_waitlisted_column_stmt;");
+
+        migrationBuilder.Sql("""
+            SET @waitlist_index_exists = (
+                SELECT COUNT(*)
+                FROM `INFORMATION_SCHEMA`.`STATISTICS`
+                WHERE `TABLE_SCHEMA` = DATABASE()
+                  AND `TABLE_NAME` = 'CourseEnrollments'
+                  AND `INDEX_NAME` = 'IX_CE_Offering_Status_WaitlistedAt'
+            );
+            """);
+        migrationBuilder.Sql("""
+            SET @add_waitlist_index_sql = IF(
+                @waitlist_index_exists = 0,
+                'CREATE INDEX `IX_CE_Offering_Status_WaitlistedAt` ON `CourseEnrollments` (`CourseSelectionOfferingId`, `Status`, `WaitlistedAt`)',
+                'SELECT 1'
+            );
+            """);
+        migrationBuilder.Sql(
+            "PREPARE add_waitlist_index_stmt FROM @add_waitlist_index_sql;");
+        migrationBuilder.Sql("EXECUTE add_waitlist_index_stmt;");
+        migrationBuilder.Sql("DEALLOCATE PREPARE add_waitlist_index_stmt;");
+    }
+
+    protected override void Down(MigrationBuilder migrationBuilder)
+    {
+        migrationBuilder.Sql("""
+            SET @waitlist_index_exists = (
+                SELECT COUNT(*)
+                FROM `INFORMATION_SCHEMA`.`STATISTICS`
+                WHERE `TABLE_SCHEMA` = DATABASE()
+                  AND `TABLE_NAME` = 'CourseEnrollments'
+                  AND `INDEX_NAME` = 'IX_CE_Offering_Status_WaitlistedAt'
+            );
+            """);
+        migrationBuilder.Sql("""
+            SET @drop_waitlist_index_sql = IF(
+                @waitlist_index_exists > 0,
+                'DROP INDEX `IX_CE_Offering_Status_WaitlistedAt` ON `CourseEnrollments`',
+                'SELECT 1'
+            );
+            """);
+        migrationBuilder.Sql(
+            "PREPARE drop_waitlist_index_stmt FROM @drop_waitlist_index_sql;");
+        migrationBuilder.Sql("EXECUTE drop_waitlist_index_stmt;");
+        migrationBuilder.Sql("DEALLOCATE PREPARE drop_waitlist_index_stmt;");
+
+        migrationBuilder.Sql("""
+            SET @waitlisted_column_exists = (
+                SELECT COUNT(*)
+                FROM `INFORMATION_SCHEMA`.`COLUMNS`
+                WHERE `TABLE_SCHEMA` = DATABASE()
+                  AND `TABLE_NAME` = 'CourseEnrollments'
+                  AND `COLUMN_NAME` = 'WaitlistedAt'
+            );
+            """);
+        migrationBuilder.Sql("""
+            SET @drop_waitlisted_column_sql = IF(
+                @waitlisted_column_exists > 0,
+                'ALTER TABLE `CourseEnrollments` DROP COLUMN `WaitlistedAt`',
+                'SELECT 1'
+            );
+            """);
+        migrationBuilder.Sql(
+            "PREPARE drop_waitlisted_column_stmt FROM @drop_waitlisted_column_sql;");
+        migrationBuilder.Sql("EXECUTE drop_waitlisted_column_stmt;");
+        migrationBuilder.Sql("DEALLOCATE PREPARE drop_waitlisted_column_stmt;");
+    }
+}