Gradio fix

app.py

@@ -119,7 +119,9 @@ with gr.Blocks() as demo:
 
     def respond(message, chat_history):
         reply = chat_fn(message, chat_history)
-        chat_history.append((message, reply))
+        # Gradio expects messages format with role/content
+        chat_history.append({"role": "user", "content": message})
+        chat_history.append({"role": "assistant", "content": reply})
         return "", chat_history
 
     send_btn.click(respond, [msg, chatbot], [msg, chatbot])