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。

src/Jiaowu.Api/Controllers/SchedulesController.cs

@@ -3,6 +3,7 @@ using System.Security.Claims;
 using System.Text.Json;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Domain.System;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Jiaowu.Api.Infrastructure.Scheduling;
 using Microsoft.AspNetCore.Authorization;
@@ -15,9 +16,7 @@ namespace Jiaowu.Api.Controllers;
 [Authorize(Roles = ManagementRoles)]
 [Route("api/schedules")]
 public sealed class SchedulesController(
-    AppDbContext db,
-    AutomaticScheduleJobQueue automaticScheduleJobQueue,
-    SchedulePublishJobQueue schedulePublishJobQueue) : ControllerBase
+    AppDbContext db) : ControllerBase
 {
     private const string ManagementRoles =
         SystemRoles.SuperAdmin + "," +
@@ -241,6 +240,10 @@ public sealed class SchedulesController(
             CurrentStep = "等待后台检查"
         };
         db.SchedulePublishJobs.Add(job);
+        db.BackgroundJobOutboxMessages.Add(
+            BackgroundJobOutboxMessage.Create(
+                BackgroundJobKind.SchedulePublish,
+                job.Id));
         try
         {
             await db.SaveChangesAsync(cancellationToken);
@@ -263,7 +266,6 @@ public sealed class SchedulesController(
                 ToResponse(existing));
         }
 
-        schedulePublishJobQueue.Enqueue(job.Id);
         return AcceptedAtAction(
             nameof(GetSchedulePublishJob),
             new { jobId = job.Id },
@@ -321,6 +323,10 @@ public sealed class SchedulesController(
             RequestedByUserId = requestedByUserId
         };
         db.AutomaticScheduleJobs.Add(job);
+        db.BackgroundJobOutboxMessages.Add(
+            BackgroundJobOutboxMessage.Create(
+                BackgroundJobKind.AutomaticSchedule,
+                job.Id));
         try
         {
             await db.SaveChangesAsync(cancellationToken);
@@ -339,7 +345,6 @@ public sealed class SchedulesController(
                 ToResponse(existing));
         }
 
-        automaticScheduleJobQueue.Enqueue(job.Id);
         return AcceptedAtAction(
             nameof(GetAutomaticScheduleJob),
             new { jobId = job.Id },