Update app.py

app.py

@@ -9,7 +9,7 @@ if not OPENAI_API_KEY:
     raise RuntimeError("Please set the OPENAI_API_KEY environment variable.")
 client = OpenAI(api_key=OPENAI_API_KEY)
 
-MODEL = "gpt-4o"
+MODEL = "o3"
 MAX_TOKENS = 1024
 
 # ---------- ❷ JSON Schema ----------