Implements OmniVoiceModelLoader with INPUT_TYPES, RETURN_TYPES, and
load_model supporting both HuggingFace auto-download and local path
sources. Adds TDD test suite and pytest infrastructure (conftest.py,
pytest.ini) to enable testing outside ComfyUI without omnivoice installed.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
