Add HF_TOKEN authentication for gated model access

app.py

@@ -1,14 +1,25 @@
 import gradio as gr
 import numpy as np
+import os
 import random
 import spaces
 import torch
 from diffusers import Flux2KleinPipeline
+from huggingface_hub import login
+
+# Authenticate with HF token for gated model access
+hf_token = os.environ.get("HF_TOKEN")
+if hf_token:
+    login(token=hf_token)
 
 dtype = torch.bfloat16
 device = "cuda" if torch.cuda.is_available() else "cpu"
 
-pipe = Flux2KleinPipeline.from_pretrained("black-forest-labs/FLUX.2-klein-9B", torch_dtype=dtype).to(device)
+pipe = Flux2KleinPipeline.from_pretrained(
+    "black-forest-labs/FLUX.2-klein-9B",
+    torch_dtype=dtype,
+    token=hf_token
+).to(device)
 
 MAX_SEED = np.iinfo(np.int32).max
 MAX_IMAGE_SIZE = 2048