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。

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

@@ -6,7 +6,8 @@ namespace Jiaowu.Api.Infrastructure.Caching;
 public enum AppCacheProfile
 {
     ReferenceData,
-    PublishedTimetable
+    PublishedTimetable,
+    Analytics
 }
 
 public interface IAppCache
@@ -106,6 +107,12 @@ public sealed class HybridAppCache(
                 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)
         };
 
@@ -146,6 +153,7 @@ public sealed class NoOpAppCache : IAppCache
 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}";
@@ -156,11 +164,30 @@ public static class AppCacheKeys
         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:{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";
 

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

@@ -10,5 +10,7 @@ public sealed class AppCacheOptions
     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;
 }