排课计算、课表发布、补考自动编排三类任务统一接入消息系统。

业务任务与 Outbox 消息同一事务落库，避免“数据库成功但消息没发出去”。
RabbitMQ 使用持久化消息、发布确认、手动 ACK、Quorum Queue、死信队列。
增加处理租约、心跳、异常重试、最大重试次数和幂等状态控制。
保留 InMemory 模式，开发环境无需安装 RabbitMQ。
支持多实例竞争消费，后续可以横向扩容。
新增 /health/messaging 消息系统健康检查。

tests/Jiaowu.Api.Tests/SchedulesControllerTests.cs

@@ -1,5 +1,6 @@
 using Jiaowu.Api.Controllers;
 using Jiaowu.Api.Domain.Academic;
+using Jiaowu.Api.Domain.System;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Scheduling;
 using Microsoft.AspNetCore.Http;
@@ -70,10 +71,7 @@ public sealed class SchedulesControllerTests
         db.AddRange(term, college, course, task, plan);
         await db.SaveChangesAsync();
 
-        var controller = new SchedulesController(
-            db,
-            new AutomaticScheduleJobQueue(),
-            new SchedulePublishJobQueue())
+        var controller = new SchedulesController(db)
         {
             ControllerContext = new ControllerContext
             {
@@ -90,6 +88,10 @@ public sealed class SchedulesControllerTests
             SchedulePlanStatus.Draft,
             (await db.SchedulePlans.SingleAsync()).Status);
         Assert.Equal(1, await db.SchedulePublishJobs.CountAsync());
+        var outbox = await db.BackgroundJobOutboxMessages.SingleAsync();
+        Assert.Equal(BackgroundJobKind.SchedulePublish, outbox.JobKind);
+        Assert.Equal(response.Id, outbox.JobId);
+        Assert.Equal(BackgroundJobOutboxState.Pending, outbox.State);
     }
 
     [Fact]
@@ -132,10 +134,7 @@ public sealed class SchedulesControllerTests
         db.AddRange(term, plan, completed);
         await db.SaveChangesAsync();
 
-        var controller = new SchedulesController(
-            db,
-            new AutomaticScheduleJobQueue(),
-            new SchedulePublishJobQueue());
+        var controller = new SchedulesController(db);
         var result = await controller.GetLatestAutomaticScheduleJob(
             plan.Id,
             CancellationToken.None);