fix: guard Chatbot messages format

app.py

@@ -105,3 +105,28 @@ with gr.Blocks(title=TITLE, theme="soft") as demo:
 
 if __name__ == "__main__":
     demo.launch(share=False, server_name="0.0.0.0", server_port=7860, show_error=True)
+
+
+    def _coerce_messages(history):
+        """確保是 [{'role','content'}] 形式。"""
+        fixed = []
+        for r, m in (history or []):
+            if isinstance(m, dict) and 'role' in m and 'content' in m:
+                fixed.append((r, m))
+            elif isinstance(m, str):
+                fixed.append((r, {"role": r, "content": m}))
+            else:
+                # 最保守兜底
+                fixed.append((r, {"role": r, "content": str(m)}))
+        return fixed
+
+    def respond(history, text, image, audio, mx, tp, top):
+        history = _coerce_messages(history)
+        history.append(("user", {"content": text}))
+        try:
+            ans = generate_reply(history, image, audio, mx, tp, top)
+        except Exception as e:
+            ans = f"(推理失敗：{e})"
+        history.append(("assistant", {"content": ans}))
+        return history, ""
+