- Python: asr_processor.py detects FPS from CUT/ffprobe (no fallback), outputs start_frame/end_frame
- Rust: All AsrSegment structs use start_time/end_time with #[serde(alias)] for backward compat
- store_asr_chunks: prefers ASR output frames, falls back to time-based conversion
- Added backward compatibility test for old JSON format (start/end)
Breaking change: ffprobe/CUT FPS failure now aborts instead of using default 24fps