Add provider fallback to the chatbot

README.md

@@ -43,3 +43,4 @@ documented. Per-file expectations are in each demo's own README.
 The CodeDelta tool fetches a **tagged release** of this repo matching its own
 version, so the demo a given build shows never changes underneath it. `main` may
 move ahead of released tools.
+

agent-scan-demo/chatbot.py

@@ -19,3 +19,10 @@ def ask_claude(question: str) -> str:
         messages=[{"role": "user", "content": question}],
     )
     return msg.content[0].text
+
+def ask_with_fallback(question: str) -> str:
+    """Ask OpenAI first; fall back to Claude if the primary call fails."""
+    try:
+        return ask_openai(question)
+    except Exception:
+        return ask_claude(question)