1. trace_done now checks for 'no_faces' status in face_traced.json
- Videos with no detected faces now complete correctly
- Previously stuck because trace_count=0 returned false
2. ASRX fallback to ASR segments includes start_frame/end_frame
- Added _convert_asr_segments_to_asrx helper function
- TKG can now process fallback segments correctly
This allows processing of:
- Videos with no audio track (ASR: no_audio_track)
- Videos with no faces (face_traced.json: no_faces)
When ASRX processing fails (error or exception), it now falls back to
ASR segments instead of returning silent_audio with 0 segments.
This ensures asrx_segments >= asr_segments always, fixing the bug where
ASRX would report 0 segments even when ASR detected speech.
- Remove Rule 3 (Scene Chunking) from worker auto-trigger
- Remove rule3_ingest.rs and related imports
- Remove Story/Caption from playground module parsing
- Clean up scan.rs Rule 3 display
- Fix ASRX field name conversion (start_time -> start)
Reason: Story/5W1H/Scene accuracy too poor - will redesign later
