Update app3.py

app3.py

@@ -30,7 +30,7 @@ SYSTEM_GUARDRAILS = (
     "Then ask the user to add the missing official details to challenge_context.txt."
 )
 
-APP_TITLE = "Challenge Copilot — RAG Q&A Bot"
+APP_TITLE = "Building AI Application Challenge Copilot"
 APP_SUBTITLE = (
     "Ask questions about the Building AI Application Challenge using the official content you put into "
     "challenge_context.txt (LlamaIndex + OpenAI)."