Address review of the noise/broadcast fixes:
- STT now refuses to run Whisper on non-speech. transcribe() runs the Silero
VAD (bundled with faster-whisper, no new dep) BEFORE the model, so noise or a
brief loud blip with no real speech never reaches STT and can't be
hallucinated into a transcript. The no_speech_prob/avg_logprob post-filter
stays as a second line of defence (a clap the VAD lets through is still killed
by Whisper's own no_speech_prob). VAD is env-tunable (VAD_THRESHOLD,
VAD_MIN_SPEECH_MS, VAD_ENABLED) and fail-open so a VAD error never swallows a
real utterance. Validated on real audio: synthesised Korean speech passes;
silence, a 50ms blip and white noise are rejected.
- Broadcast auto-start no longer blocks the voice join and no longer silently
swallows failures: wiring is synchronous, the Go-Live start runs in the
background with a bounded retry and a loud final-failure log.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
6d72e10f9c