Update app.py

app.py

@@ -44,7 +44,7 @@ class GroqAgent:
             
         # 修正：換回目前 Groq 支援的主力模型
         model = OpenAIServerModel(
-            model_id="llama-3.3-70b-versatile",
+            model_id="llama-3.1-8b-instant",
             api_base="https://api.groq.com/openai/v1",
             api_key=self.api_key
         )