Update app.py

app.py

@@ -225,9 +225,8 @@ def fetch_task_file(task_id: str, max_chars: int = 4000) -> str:
 # =====================================================
 
 llm = ChatOpenAI(
-    base_url="https://api.freemodel.dev/v1",
     api_key=FM_TOKEN,
-    model="gpt-5.5"
+    model="gpt-5.4-nano-2026-03-17"
 )
 
 chat = llm