Production deployment hardening, dub OOM recovery, new SoniTranslate sidecar engine, ASR backend expansion.
- Dub generation OOM recovery: backend/api/routers/dub_generate.py:163-209 adds OOM detection + one retry with reduced nstep
- New SoniTranslate sidecar engine: backend/api/routers/sonitranslate.py + backend/services/sonitranslate.py (subprocess-based dubbing pipeline, opt-in)
- ASR backends expansion: backend/services/asr_backend.py adds NeMo Parakeet TDT, Moonshine, additional Whisper variants; new GET /system/asr-backends endpoint
- Dub UI polish: tighter spacing in DubSegmentRow.css, DubTab.css
Issue #78 (speaker diarization mis-assignment) NOT addressed by this PR — the bundled diarization changes are in the new SoniTranslate sidecar, not the existing pyannote pipeline. Keeping #78 open.
No DB schema changes, no migration. Backward-compatible for existing user data.