refactor: 统一使用现代类型注解替代传统类型注解

- 将 Dict、List 等传统类型注解替换为 dict、list 等现代类型注解
- 更新类型注解以更精确地反映变量类型
- 修复部分类型注解与实际使用不匹配的问题
- 优化部分代码逻辑以提高类型安全性

bot/handler.py

@@ -7,6 +7,7 @@ import json
 import logging
 import threading
 import time
+from typing import Any, Dict
 
 import lark_oapi as lark
 from lark_oapi.api.im.v1 import P2ImMessageReceiveV1
@@ -25,7 +26,7 @@ _last_message_time: float = 0.0
 _reconnect_count: int = 0
 
 
-def get_ws_status() -> dict:
+def get_ws_status() -> dict[str, Any]:
     """Return WebSocket connection status."""
     return {
         "connected": _ws_connected,
@@ -39,8 +40,17 @@ def _handle_message(data: P2ImMessageReceiveV1) -> None:
     _last_message_time = time.time()
 
     try:
-        message = data.event.message
-        sender = data.event.sender
+        event = data.event
+        if event is None:
+            logger.warning("Received event with no data")
+            return
+
+        message = event.message
+        sender = event.sender
+
+        if message is None:
+            logger.warning("Received event with no message")
+            return
 
         logger.debug(
             "event type=%r chat_type=%r content=%r",
@@ -53,7 +63,7 @@ def _handle_message(data: P2ImMessageReceiveV1) -> None:
             logger.info("Skipping non-text message_type=%r", message.message_type)
             return
 
-        chat_id: str = message.chat_id
+        chat_id: str = message.chat_id or ""
         raw_content: str = message.content or "{}"
         content_obj = json.loads(raw_content)
         text: str = content_obj.get("text", "").strip()
@@ -119,8 +129,9 @@ async def _process_message(user_id: str, chat_id: str, text: str) -> None:
                 if nodes:
                     lines = ["Connected Nodes:"]
                     for n in nodes:
-                        marker = " → " if n.get("node_id") == registry.get_active_node(user_id) else "   "
-                        lines.append(f"{marker}{n['display_name']}  sessions={n['sessions']}  {n['status']}")
+                        active_node = registry.get_active_node(user_id)
+                        marker = " → " if n.get("node_id") == (active_node.node_id if active_node else None) else "   "
+                        lines.append(f"{marker}{n.get('display_name', 'unknown')}  sessions={n.get('sessions', 0)}  {n.get('status', 'unknown')}")
                     lines.append("\nUse \"/node <name>\" to switch active node.")
                     await send_text(chat_id, "chat_id", "\n".join(lines))
                 else:
@@ -144,7 +155,9 @@ async def _process_message(user_id: str, chat_id: str, text: str) -> None:
 
 def _handle_any(data: lark.CustomizedEvent) -> None:
     """Catch-all handler to log any event the SDK receives."""
-    logger.info("RAW CustomizedEvent: %s", lark.JSON.marshal(data)[:500])
+    marshaled = lark.JSON.marshal(data)
+    if marshaled:
+        logger.info("RAW CustomizedEvent: %s", marshaled[:500])
 
 
 def build_event_handler() -> lark.EventDispatcherHandler: