主要改动：

自动排课接口立即返回 202 + jobId
后台服务独立执行，不受浏览器关闭或前端超时影响
进度、成功、失败状态持久化到数据库
服务重启后自动恢复排队中或中断的任务
同一草稿禁止重复提交后台任务
运行期间禁止编辑、发布或删除该课表
排课结果和任务成功状态在同一事务中提交
前端每秒轮询进度，显示已处理教学班和已规划安排数

src/Jiaowu.Api/Domain/Academic/ScheduleEntities.cs

@@ -65,6 +65,24 @@ public sealed class TeachingTaskAllowedClassroom
     public Classroom? Classroom { get; set; }
 }
 
+public sealed class AutomaticScheduleJob : EntityBase
+{
+    public Guid SchedulePlanId { get; set; }
+    public SchedulePlan? SchedulePlan { get; set; }
+    public Guid? ActiveSchedulePlanId { get; set; }
+    public Guid? RequestedByUserId { get; set; }
+    public AutomaticScheduleJobStatus Status { get; set; } =
+        AutomaticScheduleJobStatus.Queued;
+    public int TotalTasks { get; set; }
+    public int ProcessedTasks { get; set; }
+    public int CreatedEntries { get; set; }
+    public int CompletedTasks { get; set; }
+    public string? MessagesJson { get; set; }
+    public string? ErrorMessage { get; set; }
+    public DateTime? StartedAt { get; set; }
+    public DateTime? CompletedAt { get; set; }
+}
+
 public enum SchedulePlanStatus
 {
     Draft = 1,
@@ -72,6 +90,14 @@ public enum SchedulePlanStatus
     Archived = 3
 }
 
+public enum AutomaticScheduleJobStatus
+{
+    Queued = 1,
+    Running = 2,
+    Succeeded = 3,
+    Failed = 4
+}
+
 public enum WeekPattern
 {
     All = 1,