Fix demo-mode startup by switching from invalid graph.run(...) to the current LangGraph stream API.: update main.py

main.py

@@ -175,7 +175,10 @@ def run_demo() -> None:
     print("Code under review:")
     print(initial_state["code"])
 
-    final_state = graph.run(initial_state)
+    final_state = initial_state.copy()
+    for chunk in graph.stream(initial_state, stream_mode="updates"):
+        for _, update in chunk.items():
+            final_state.update(update)
 
     print()
     print("=== Final Result ===")