主要变更：

新增统一缓存封装：[AppCache.cs (line 12)](/E:/jiaowu/src/Jiaowu.Api/Infrastructure/Caching/AppCache.cs:12)
接入 HybridCache 和可选 Redis：[Program.cs (line 153)](/E:/jiaowu/src/Jiaowu.Api/Program.cs:153)
缓存学生激活选项、基础数据、公开课表和课表选项。
个人课表、选课容量、成绩、权限、通知和任务状态保持实时查询。
基础数据、课程、教师、教学任务、作息、考试和课表发布后自动失效相关缓存。
新增 /health/cache，Redis 故障不影响 /health/ready。
Compose 增加 256MB、allkeys-lfu、无持久化的 redis:8.8-alpine 服务；该镜像标签已由 Docker 官方镜像仓库核对。
更新 [.env.example (line 1)](/E:/jiaowu/.env.example:1) 和 [README.md (line 190)](/E:/jiaowu/README.md:190) 部署说明。

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 + "," +
@@ -389,6 +391,7 @@ public sealed class TeachingTasksController(
         try
         {
             await db.SaveChangesAsync(cancellationToken);
+            await cache.RemoveByTagAsync(AppCacheTags.Timetables, cancellationToken);
             return Ok(new { AffectedCount = tasks.Count });
         }
         catch (DbUpdateException)
@@ -544,6 +547,9 @@ 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,
@@ -737,6 +743,7 @@ 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)