Add vLLM-Omni library info to Hugging Face Hub requests (#5381)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>
Co-authored-by: Hongsheng Liu <liuhongsheng4@huawei.com>
Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

vllm_omni/engine/arg_utils.py

@@ -381,9 +381,9 @@ class OmniEngineArgs(EngineArgs):
                 if tokenizer_subfolder:
                     # Download just the tokenizer files from the subfolder
                     try:
-                        from huggingface_hub import snapshot_download
+                        from vllm_omni.transformers_utils.repo_utils import hf_api
 
-                        local_dir = snapshot_download(
+                        local_dir = hf_api().snapshot_download(
                             model_path,
                             allow_patterns=[
                                 f"{tokenizer_subfolder}/tokenizer*",