chore: change model

.env.example

@@ -1,3 +1,2 @@
 SPACE_ID=
-SPACE_HOST=
-OPENROUTER_KEY=
+SPACE_HOST=

agent.py

@@ -1,14 +1,14 @@
 import gradio as gr
 import random
 import os
-from smolagents import DuckDuckGoSearchTool, CodeAgent, WikipediaSearchTool, LiteLLMModel
+from smolagents import DuckDuckGoSearchTool, CodeAgent, WikipediaSearchTool, HfApiModel
 from tools import DownloadTaskAttachmentTool, VisitWebpageTool
 
 
 class MyAgent:
     def __init__(self):
         self.agent = CodeAgent(
-            model=LiteLLMModel(model_id="openrouter/meta-llama/llama-4-maverick:free", api_key=os.getenv("OPENROUTER_KEY")),
+            model=HfApiModel(),
             tools=[DuckDuckGoSearchTool(), WikipediaSearchTool(), VisitWebpageTool(), DownloadTaskAttachmentTool()],
             add_base_tools=True,
             additional_authorized_imports=['pandas', 'numpy', 'csv', 'subprocess', 'exec']