When yt-dlp yields no subtitle files, the server now runs
scripts/transcribe.py (faster-whisper, large-v3-turbo, CUDA with CPU
fallback) on the downloaded media and feeds the resulting VTT through
the existing Markdown conversion.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01P1w53ybPWArpZpcei9JPYX
