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。

tests/Jiaowu.Api.Tests/ScheduleSettingsControllerTests.cs

@@ -1,5 +1,6 @@
 using Jiaowu.Api.Controllers;
 using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.AspNetCore.Mvc;
 using Microsoft.Data.Sqlite;
@@ -70,7 +71,7 @@ public sealed class ScheduleSettingsControllerTests
             secondTask);
         await db.SaveChangesAsync();
 
-        var controller = new ScheduleSettingsController(db);
+        var controller = new ScheduleSettingsController(db, NoOpAppCache.Instance);
         var result = await controller.SaveConstraintsBatch(
             new TeachingTaskScheduleConstraintBatchRequest(
                 term.Id,
@@ -174,7 +175,7 @@ public sealed class ScheduleSettingsControllerTests
         db.AddRange(college, course, term, teacher, classroom, task, constraint);
         await db.SaveChangesAsync();
 
-        var result = await new ScheduleSettingsController(db)
+        var result = await new ScheduleSettingsController(db, NoOpAppCache.Instance)
             .GetConstraints(term.Id, CancellationToken.None);
 
         var ok = Assert.IsType<OkObjectResult>(result);
@@ -269,20 +270,26 @@ public sealed class ScheduleSettingsControllerTests
         await db.SaveChangesAsync();
         db.ChangeTracker.Clear();
 
-        var result = await new ScheduleSettingsController(db)
+        var result = await new ScheduleSettingsController(db, NoOpAppCache.Instance)
             .GetConstraints(term.Id, CancellationToken.None);
 
         var ok = Assert.IsType<OkObjectResult>(result);
         var payload = Assert.IsAssignableFrom<IEnumerable>(ok.Value);
         Assert.Contains(payload.Cast<object>(), item =>
             JsonSerializer.Serialize(item).Contains(task.TaskNumber));
-        var timeSlotsResult = await new ScheduleSettingsController(db)
+        var timeSlotsResult = await new ScheduleSettingsController(
+                db,
+                NoOpAppCache.Instance)
             .GetTimeSlots(term.Id, CancellationToken.None);
         var timeSlotsOk = Assert.IsType<OkObjectResult>(timeSlotsResult);
         var timeSlotsJson = JsonSerializer.Serialize(timeSlotsOk.Value);
         Assert.Contains("08:00", timeSlotsJson);
 
-        var examTimeSlotsResult = await new ExamsController(db, null!, null!)
+        var examTimeSlotsResult = await new ExamsController(
+                db,
+                null!,
+                null!,
+                NoOpAppCache.Instance)
             .GetTimeSlotsForTerm(term.Id, CancellationToken.None);
         var examTimeSlotsOk =
             Assert.IsType<OkObjectResult>(examTimeSlotsResult);