“教学班成绩分析”页面新增“定时刷新设置”，支持启停、刷新间隔、单次处理上限、查看上次/下次扫描时间。

配置保存在独立数据库表 CourseGradeStatisticsRefreshSettings，不是修改 appsettings.json。
后台每 10 秒读取配置，仅到期扫描；成绩录入、导入、审批时不再立即创建统计任务。
扫描发现过期数据后，仍通过持久任务、Outbox 和 RabbitMQ 执行；Redis统计缓存由处理任务统一刷新。

src/Jiaowu.Api/Infrastructure/Persistence/DevelopmentSqliteMigrator.cs

@@ -98,6 +98,8 @@ public sealed class DevelopmentSqliteMigrator(
         "20260809_51_separate_experiment_classroom_scope";
     private const string ReusableCourseGroupsMigration =
         "20260809_52_reusable_course_groups";
+    private const string CourseGradeStatisticsRefreshSettingsMigration =
+        "20260809_53_course_grade_statistics_refresh_settings";
 
     public async Task MigrateAsync(CancellationToken cancellationToken = default)
     {
@@ -677,6 +679,14 @@ public sealed class DevelopmentSqliteMigrator(
             TeachingTaskGradeAnalyticsMigration,
             TeachingTaskGradeAnalyticsStatements,
             cancellationToken);
+        var gradeRefreshSettingsExist = await db.Database
+            .SqlQueryRaw<int>(
+                "SELECT COUNT(*) AS \"Value\" FROM sqlite_master WHERE type = 'table' AND name = 'CourseGradeStatisticsRefreshSettings'")
+            .AnyAsync(value => value > 0, cancellationToken);
+        await ApplyMigrationAsync(
+            CourseGradeStatisticsRefreshSettingsMigration,
+            gradeRefreshSettingsExist ? [] : CourseGradeStatisticsRefreshSettingsStatements,
+            cancellationToken);
         var swaggerSettingsExist = await db.Database
             .SqlQueryRaw<int>(
                 "SELECT COUNT(*) AS \"Value\" FROM sqlite_master WHERE type = 'table' AND name = 'SystemFeatureSettings'")
@@ -2973,6 +2983,12 @@ public sealed class DevelopmentSqliteMigrator(
         """
     ];
 
+    private static readonly string[] CourseGradeStatisticsRefreshSettingsStatements =
+    [
+        """CREATE TABLE IF NOT EXISTS "CourseGradeStatisticsRefreshSettings" ("Id" TEXT NOT NULL CONSTRAINT "PK_CourseGradeStatisticsRefreshSettings" PRIMARY KEY, "Key" TEXT NOT NULL, "IsEnabled" INTEGER NOT NULL, "IntervalSeconds" INTEGER NOT NULL, "BatchSize" INTEGER NOT NULL, "LastRunAt" TEXT NULL, "CreatedAt" TEXT NOT NULL, "UpdatedAt" TEXT NOT NULL);""",
+        """CREATE UNIQUE INDEX IF NOT EXISTS "IX_CourseGradeStatisticsRefreshSettings_Key" ON "CourseGradeStatisticsRefreshSettings" ("Key");"""
+    ];
+
     private static readonly string[] ExperimentClassroomConstraintStatements =
     [
         """