修复Gradio兼容性问题：指定chatbot type参数，简化代码结构

app.py

@@ -121,7 +121,7 @@ def stream_response(
         yield chat_history, ""
 
 
-with gr.Blocks(title="StepFun - Step3 Multimodal Chat", theme=gr.themes.Soft()) as demo:
+with gr.Blocks(title="StepFun - Step3 Multimodal Chat") as demo:
     gr.Markdown("""
     # StepFun Step-3 多模态对话（Hugging Face Space）
     - 支持上传图片 + 文本提问，后端接口兼容 OpenAI Chat Completions。
@@ -149,7 +149,7 @@ with gr.Blocks(title="StepFun - Step3 Multimodal Chat", theme=gr.themes.Soft())
         lines=2,
     )
 
-    chatbot = gr.Chatbot(height=420, show_label=False)
+    chatbot = gr.Chatbot(height=420, show_label=False, type="tuples")
 
     with gr.Row():
         image = gr.Image(label="上传图片（可选）", type="pil")
@@ -175,4 +175,4 @@ with gr.Blocks(title="StepFun - Step3 Multimodal Chat", theme=gr.themes.Soft())
 
 if __name__ == "__main__":
     # 本地调试：python app.py
-    demo.queue().launch(server_name="0.0.0.0", server_port=int(os.environ.get("PORT", 7860)))
+    demo.launch(server_name="0.0.0.0", server_port=int(os.environ.get("PORT", 7860)), share=False)