The model_path was being converted to a Path object and then back to string
for from_pretrained() calls. This is unnecessary since HuggingFace accepts
strings directly, and causes issues on Windows where Path() converts forward
slashes to backslashes (e.g., "microsoft/VibeVoice-Realtime-0.5B" becomes
"microsoft\VibeVoice-Realtime-0.5B").
This fix:
- Keeps model_path as a string (no behavior change on Linux/macOS)
- Fixes Windows compatibility for HuggingFace repo IDs
- Removes redundant str() conversions
YaoyaoChang