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/Infrastructure/Exams/MakeupExamAutoJobs.cs

@@ -1,111 +1,10 @@
 using System.Text.Json;
-using System.Threading.Channels;
 using Jiaowu.Api.Domain.Academic;
 using Jiaowu.Api.Infrastructure.Persistence;
 using Microsoft.EntityFrameworkCore;
 
 namespace Jiaowu.Api.Infrastructure.Exams;
 
-public sealed class MakeupExamAutoJobQueue
-{
-    private readonly Channel<Guid> _channel = Channel.CreateUnbounded<Guid>(
-        new UnboundedChannelOptions
-        {
-            SingleReader = true,
-            SingleWriter = false
-        });
-
-    public void Enqueue(Guid jobId)
-    {
-        if (!_channel.Writer.TryWrite(jobId))
-            throw new InvalidOperationException("补考自动生成任务队列当前不可用。");
-    }
-
-    public IAsyncEnumerable<Guid> ReadAllAsync(CancellationToken cancellationToken) =>
-        _channel.Reader.ReadAllAsync(cancellationToken);
-}
-
-public sealed class MakeupExamAutoJobWorker(
-    IServiceScopeFactory scopeFactory,
-    MakeupExamAutoJobQueue queue,
-    ILogger<MakeupExamAutoJobWorker> logger) : BackgroundService
-{
-    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
-    {
-        try
-        {
-            await RecoverInterruptedJobsAsync(stoppingToken);
-        }
-        catch (Exception exception)
-        {
-            logger.LogWarning(
-                exception,
-                "Could not recover makeup exam auto jobs (table may not exist yet).");
-        }
-
-        try
-        {
-            await foreach (var jobId in queue.ReadAllAsync(stoppingToken))
-            {
-                try
-                {
-                    await using var scope = scopeFactory.CreateAsyncScope();
-                    var processor = scope.ServiceProvider
-                        .GetRequiredService<MakeupExamAutoJobProcessor>();
-                    await processor.ProcessAsync(jobId, stoppingToken);
-                }
-                catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
-                {
-                    throw;
-                }
-                catch (Exception exception)
-                {
-                    logger.LogError(
-                        exception,
-                        "Unexpected failure while dispatching makeup exam auto job {JobId}.",
-                        jobId);
-                }
-            }
-        }
-        catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested)
-        {
-            logger.LogInformation("Makeup exam auto job worker is stopping.");
-        }
-    }
-
-    private async Task RecoverInterruptedJobsAsync(CancellationToken cancellationToken)
-    {
-        await using var scope = scopeFactory.CreateAsyncScope();
-        var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
-        var jobs = await db.MakeupExamAutoJobs
-            .Where(x =>
-                x.Status == MakeupExamAutoJobStatus.Queued ||
-                x.Status == MakeupExamAutoJobStatus.Running)
-            .OrderBy(x => x.CreatedAt)
-            .ToListAsync(cancellationToken);
-
-        foreach (var job in jobs)
-        {
-            job.Status = MakeupExamAutoJobStatus.Queued;
-            job.StartedAt = null;
-            job.CompletedAt = null;
-            job.ErrorMessage = null;
-        }
-
-        if (jobs.Count > 0)
-            await db.SaveChangesAsync(cancellationToken);
-        foreach (var job in jobs)
-            queue.Enqueue(job.Id);
-
-        if (jobs.Count > 0)
-        {
-            logger.LogInformation(
-                "Recovered {JobCount} queued or interrupted makeup exam auto jobs.",
-                jobs.Count);
-        }
-    }
-}
-
 public sealed class MakeupExamAutoJobProcessor(
     AppDbContext db,
     MakeupExamEligibilityService eligibilityService,