ROOT CAUSE FOUND: tag_audio_events=false caused Scribe to stop transcribing
when instrumental music dominates (polka harmonica taking over from vocals).
Real-world test on Avseniki - Ena bolha za pomoč (186s polka):
- tag_audio_events=false: 20% coverage (37s only) — fails
- tag_audio_events=true: 100% coverage (186s full) — works
When tag_audio_events=true, Scribe inserts placeholder markers like
'(glasba)' / '(plesalna glasba)' for instrumental sections instead of
giving up. We then filter these out so they don't appear in subtitles.
Filtering logic:
- Skip word.type != 'word' (audio_event types)
- Skip parenthesized text legacy fallback like '(music)', '(applause)'
This is the core fix — no longer reliant on filename for transcription
completeness. Even untitled files like '12345.mp4' now get full coverage.