修改样式，接口

chat/api/v1/vo.py

@@ -0,0 +1,20 @@
+from pydantic import BaseModel
+from datetime import datetime
+
+class MessageVO(BaseModel):
+    id: int
+    content: str
+    conversation_id: int
+    type: str
+
+    class Config:
+        from_attributes = True  # 启用ORM模式支持
+
+class ConversationsVO(BaseModel):
+    id: int
+    title: str
+    update_time: datetime
+    last_message: str | None = None
+    
+    class Config:
+        from_attributes = True