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/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 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);
-        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 })
-            .ToListAsync(cancellationToken);
-        return Ok(new
-        {
-            Colleges = colleges,
-            Majors = majors,
-            Classes = classes,
-            Grades = classes.Select(x => x.Grade).Distinct().OrderByDescending(x => x)
-        });
+        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 ActivationCollegeOption(x.Id, x.Code, x.Name))
+                    .ToListAsync(token);
+                var majors = await db.Majors.AsNoTracking()
+                    .Where(x => x.IsEnabled && x.College!.IsEnabled)
+                    .OrderBy(x => x.Code)
+                    .Select(x => new ActivationMajorOption(
+                        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)
+                    .OrderByDescending(x => x.Grade)
+                    .ThenBy(x => x.Code)
+                    .Select(x => new ActivationClassOption(
+                        x.Id, x.Code, x.Name, x.Grade, x.MajorId))
+                    .ToListAsync(token);
+                return new ActivationOptionsResponse(
+                    colleges,
+                    majors,
+                    classes,
+                    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);