将@抽取与社交图写入改为定时批处理

- 精简 archive_message 主链路：仅做消息归档，不再同步执行@解析与社交统计

- 新增 MessageStorageDB.process_pending_mentions 批处理能力，按批次回填 mentioned_user_ids 并写入社交图

- 新增系统任务 process_pending_mentions，每10分钟执行一次（every_seconds=600）

- 增加幂等保护：基于 t_message_mentions 已有记录过滤新增@关系，避免重复累加社交边和热度

- 保留详细中文注释，说明性能优化目标与批处理策略

utils/system_jobs.py

@@ -43,6 +43,14 @@ def get_system_job_definitions(robot) -> List[Dict[str, Any]]:
             "trigger_config": {"seconds": 300},
             "handler": _build_process_pending_images_handler(robot),
         },
+        {
+            "job_key": "process_pending_mentions",
+            "name": "待抽取@关系处理",
+            "description": "每 10 分钟处理一次待抽取@消息并更新社交图",
+            "trigger_type": "every_seconds",
+            "trigger_config": {"seconds": 600},
+            "handler": _build_process_pending_mentions_handler(robot),
+        },
     ]
 
 def _build_process_pending_images_handler(robot) -> Callable[[], Awaitable[None]]:
@@ -53,6 +61,14 @@ def _build_process_pending_images_handler(robot) -> Callable[[], Awaitable[None]
     return _handler
 
 
+def _build_process_pending_mentions_handler(robot) -> Callable[[], Awaitable[None]]:
+    async def _handler():
+        if hasattr(robot, "message_storage") and robot.message_storage:
+            await robot.message_storage.process_pending_mentions(batch_size=200, max_age_days=7)
+
+    return _handler
+
+
 class SystemJobLoader:
     """系统任务加载器：从数据库读取调度配置并注册到 async_job。"""