fix(schedule): reseed default system jobs before DB reload

utils/system_jobs.py

@@ -150,6 +150,9 @@ class SystemJobLoader:
             )
 
     def reload_from_db(self):
+        # 每次重载前先补齐默认任务，避免误删后无法恢复
+        self._seed_defaults()
+
         # 先移除当前注册任务，避免重复调度
         for job_id in self._registered_job_ids:
             async_job.remove_job(job_id)