update model setting

agent.py

@@ -84,9 +84,9 @@ def image_caption(dir: str) -> str:
 class BasicAgent:
     def __init__(self):
         model = ChatGoogleGenerativeAI(
-            model="gemini-2.0-flash",
+            model="gemini-2.0-flash-lite",
             temperature=0,
-            max_tokens=None,
+            max_tokens=1024,
             timeout=None,
             max_retries=2,
             google_api_key="AIzaSyAxVUPaGJIgdxB46ZR0RWPKSjB9a63Z80o",