Enable show_error so runtime exceptions surface in the UI

app.py

@@ -549,4 +549,4 @@ with gr.Blocks(title="Play ChessMamba") as demo:
         undo_btn.click(undo, inputs=[history, side_radio, top_k], outputs=OUT)
 
 if __name__ == "__main__":
-    demo.launch(mcp_server=True, theme=gr.themes.Citrus(), css=CSS)
+    demo.launch(mcp_server=True, theme=gr.themes.Citrus(), css=CSS, show_error=True)