回滚：移除告警处理图片字段，告警只记录状态

告警只需记录处理状态（已处理/误报），图片等信息在工单体系中管理。
移除 handle_image_url 字段、自动迁移和相关参数。

app/routers/yudao_aiot_alarm.py

@@ -101,7 +101,6 @@ async def _alarm_to_camel(alarm_dict: dict, camera_info_map: dict = None, camera
         "edgeNodeId": alarm_dict.get("edge_node_id"),
         "handler": alarm_dict.get("handler"),
         "handleRemark": alarm_dict.get("handle_remark"),
-        "handleImageUrl": alarm_dict.get("handle_image_url"),
         "handledAt": alarm_dict.get("handled_at"),
         "createdAt": alarm_dict.get("created_at"),
         "updatedAt": alarm_dict.get("updated_at"),
@@ -220,7 +219,6 @@ async def handle_alert(
     handleStatus: Optional[str] = Query(None, description="处理状态: HANDLING/DONE/IGNORED"),
     status: Optional[str] = Query(None, description="处理状态（兼容旧接口）"),
     remark: Optional[str] = Query(None, description="处理备注"),
-    handleImageUrl: Optional[str] = Query(None, description="处理图片URL"),
     service: AlarmEventService = Depends(get_alarm_event_service),
     current_user: dict = Depends(get_current_user)
 ):
@@ -244,7 +242,6 @@ async def handle_alert(
         handle_status=handleStatus,
         remark=remark,
         handler=handler,
-        handle_image_url=handleImageUrl,
     )
     if not alarm:
         raise HTTPException(status_code=404, detail="告警不存在")