完成请求推送，但组装mes还有问题

backend/services/chat_service.py

@@ -57,7 +57,7 @@ class ChatService:
                 logger.error(f"处理角色目录 {role_dir.name} 时出错: {str(e)}")
                 continue
         
-        return {"chat": [{"role_name": role, **chat} for role, chats in result.items() for chat in chats]}
+        return result
     
     def _get_chat_summary(self, role_name: str, chat_name: str) -> Optional[Dict]:
         """
@@ -197,7 +197,8 @@ class ChatService:
         tags = []
         
         try:
-            character_file = Path("data/characters") / role_name / "character.json"
+            from backend.core.config import settings
+            character_file = settings.CHARACTERS_PATH / role_name / "character.json"
             if character_file.exists():
                 with open(character_file, 'r', encoding='utf-8') as f:
                     character_data = json.load(f)