added login for gated models

app.py

@@ -29,6 +29,12 @@ def pil_to_binstring(img: Image.Image, thresh: int = 128) -> str:
 _LLM_CACHE = {}  # model_id -> (tokenizer, model)
 
 def load_llm(model_id: str):
+    # Add authentication for gated models
+    from huggingface_hub import login
+    token = os.environ.get("HF_TOKEN")
+    if token:
+        login(token=token)
+        
     if model_id in _LLM_CACHE:
         return _LLM_CACHE[model_id]