feat: add session management to MessageChain

- Implemented session ID creation and reuse based on user activity, with a timeout of 15 minutes.
- Added remote command to clear user sessions, enhancing user session management capabilities.
- Updated Command class to include a new command for clearing sessions.

app/command.py

@@ -5,6 +5,7 @@ from typing import Any, Union, Dict, Optional
 
 from app.chain import ChainBase
 from app.chain.download import DownloadChain
+from app.chain.message import MessageChain
 from app.chain.site import SiteChain
 from app.chain.subscribe import SubscribeChain
 from app.chain.system import SystemChain
@@ -140,6 +141,12 @@ class Command(metaclass=Singleton):
                 "description": "当前版本",
                 "category": "管理",
                 "data": {}
+            },
+            "/clear_session": {
+                "func": MessageChain().remote_clear_session,
+                "description": "清除会话",
+                "category": "管理",
+                "data": {}
             }
         }
         # 插件命令集合