系统定时任务日志持久化：新增入库与后台查询

- 新增系统任务日志表 t_system_job_logs，持久化记录每次执行结果、摘要、耗时、详情JSON\n- SystemJobLoader 注册任务时增加执行包装器：成功/失败均写入数据库日志，失败后继续抛出保证运行态状态一致\n- 系统任务后台日志接口改为查询数据库日志（不再依赖仅内存的 async_job logs），解决重启后日志丢失问题\n- 保持前端日志字段兼容，接口返回映射为 time/level/message 结构

admin/dashboard/blueprints/system_jobs.py

@@ -94,12 +94,24 @@ def api_trigger_job(job_key: str):
 @system_jobs_bp.route("/api/jobs/<job_key>/logs", methods=["GET"])
 @login_required
 def api_job_logs(job_key: str):
-    job_id = async_job.get_job_id_by_key(job_key)
-    if not job_id:
-        return jsonify({"success": True, "data": []})
-
+    server = current_app.dashboard_server
     limit = int(request.args.get("limit", 100))
-    logs = async_job.get_job_logs(job_id, limit=limit)
+    db_logs = server.system_job_db.get_job_logs(job_key, limit=limit)
+    # 为了兼容前端既有表头(time/level/message)，这里做一层字段映射。
+    logs = []
+    for row in db_logs:
+        status = str(row.get("status") or "")
+        level = "error" if status == "failed" else ("success" if status == "success" else "info")
+        logs.append(
+            {
+                "time": row.get("triggered_at"),
+                "level": level,
+                "message": row.get("summary") or "",
+                "status": status,
+                "duration_ms": row.get("duration_ms"),
+                "detail_json": row.get("detail_json") or {},
+            }
+        )
     return jsonify({"success": True, "data": logs})