Add @spaces.GPU stub for ZeroGPU runtime check

app.py

@@ -3,6 +3,7 @@ import gradio as gr
 import requests
 import inspect
 import pandas as pd
+import spaces
 from langchain_huggingface import ChatHuggingFace, HuggingFaceEndpoint
 from typing import TypedDict, Annotated
 from langgraph.graph.message import add_messages
@@ -14,6 +15,11 @@ from langchain_core.messages import AnyMessage, HumanMessage
 DEFAULT_API_URL = "https://agents-course-unit4-scoring.hf.space"
 
 
+@spaces.GPU
+def _zerogpu_stub():
+    return None
+
+
 # --- Basic Agent Definition ---
 # ----- THIS IS WERE YOU CAN BUILD WHAT YOU WANT ------
 
@@ -251,4 +257,4 @@ if __name__ == "__main__":
     print("-" * (60 + len(" App Starting ")) + "\n")
 
     print("Launching Gradio Interface for Basic Agent Evaluation...")
-    demo.launch(debug=True, share=False)
+    demo.launch(debug=True, share=True)