fix: 改进图片显示和移除调试输出

优化图片链接格式，在图片前后添加空行以改善显示效果
注释掉OpenAI聊天服务中的调试打印语句

app/handler/response_handler.py

@@ -209,7 +209,7 @@ def _extract_image_data(part: dict) -> str:
     bytes_data = base64.b64decode(base64_data)
     upload_response = image_uploader.upload(bytes_data,filename)
     if upload_response.success:
-        text = f"![image]({upload_response.data.url})"
+        text = f"\n\n![image]({upload_response.data.url})\n\n"
     else:
         text = ""
     return text

app/service/chat/openai_chat_service.py

@@ -205,7 +205,7 @@ class OpenAIChatService:
                 async for line in self.api_client.stream_generate_content(
                     payload, model, api_key
                 ):
-                    print(line)
+                    # print(line)
                     if line.startswith("data:"):
                         chunk = json.loads(line[6:])
                         openai_chunk = self.response_handler.handle_response(