仪表盘和 6 类统计摘要接入 HybridCache（内存 + Redis）。

默认 Redis 缓存 3 分钟、本地缓存 30 秒，可通过环境变量调整。
缓存键包含数据权限范围、有效学院和全部筛选条件，避免跨学院串数据。
Excel 导出保持实时查询，不使用摘要缓存。
无需数据库迁移。

tests/Jiaowu.Api.Tests/AppCacheTests.cs

@@ -1,3 +1,4 @@
+using System.Text.Json;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Infrastructure.Caching;
 using Jiaowu.Api.Infrastructure.Timetables;
@@ -12,6 +13,51 @@ namespace Jiaowu.Api.Tests;
 
 public sealed class AppCacheTests
 {
+    [Fact]
+    public void Statistics_keys_isolate_data_scope_college_and_filters()
+    {
+        var firstCollege = Guid.NewGuid();
+        var secondCollege = Guid.NewGuid();
+        var term = Guid.NewGuid().ToString("N");
+
+        var first = AppCacheKeys.Statistics(
+            "grades",
+            "College",
+            firstCollege,
+            term,
+            "-");
+        var otherCollege = AppCacheKeys.Statistics(
+            "grades",
+            "College",
+            secondCollege,
+            term,
+            "-");
+        var otherScope = AppCacheKeys.Statistics(
+            "grades",
+            "All",
+            firstCollege,
+            term,
+            "-");
+        var otherFilter = AppCacheKeys.Statistics(
+            "grades",
+            "College",
+            firstCollege,
+            Guid.NewGuid().ToString("N"),
+            "-");
+
+        Assert.NotEqual(first, otherCollege);
+        Assert.NotEqual(first, otherScope);
+        Assert.NotEqual(first, otherFilter);
+        Assert.Equal(
+            first,
+            AppCacheKeys.Statistics(
+                " GRADES ",
+                "COLLEGE",
+                firstCollege,
+                term,
+                null));
+    }
+
     [Fact]
     public async Task Hybrid_cache_reuses_value_and_tag_invalidation_reloads_source()
     {
@@ -122,6 +168,56 @@ public sealed class AppCacheTests
         Assert.Equal(new TimeOnly(8, 45), result.Slots.Single().EndsAt);
     }
 
+    [Fact]
+    public async Task Analytics_json_round_trips_through_distributed_cache()
+    {
+        IDistributedCache distributedCache = new SharedDistributedCache(
+            new MemoryDistributedCache(
+                Options.Create(new MemoryDistributedCacheOptions())));
+        var keyPrefix = $"tests:{Guid.NewGuid():N}";
+        var source = JsonSerializer.SerializeToElement(new
+        {
+            totals = new { totalCourses = 3 }
+        });
+
+        await using (var writer = CreateProvider(
+                         true,
+                         distributedCache,
+                         keyPrefix))
+        {
+            await writer.GetRequiredService<IAppCache>().GetOrCreateAsync(
+                "statistics:courses",
+                _ => Task.FromResult(source),
+                AppCacheProfile.Analytics,
+                [AppCacheTags.Analytics],
+                CancellationToken.None);
+        }
+
+        await using var reader = CreateProvider(
+            true,
+            distributedCache,
+            keyPrefix);
+        var sourceCalled = false;
+        var result = await reader.GetRequiredService<IAppCache>()
+            .GetOrCreateAsync(
+                "statistics:courses",
+                _ =>
+                {
+                    sourceCalled = true;
+                    return Task.FromResult(source);
+                },
+                AppCacheProfile.Analytics,
+                [AppCacheTags.Analytics],
+                CancellationToken.None);
+
+        Assert.False(sourceCalled);
+        Assert.Equal(
+            3,
+            result.GetProperty("totals")
+                .GetProperty("totalCourses")
+                .GetInt32());
+    }
+
     private static ServiceProvider CreateProvider(
         bool enabled,
         IDistributedCache? distributedCache = null,