SKILL.md: - Step 6: two clip modes — video-only (frame extraction) vs all-streams (editor use) - Pitfall #10: warn about dropping audio tracks with default -map 0:v:0 - Note on keyframe accuracy vs frame-exact re-encode extract_frames.py: - New --all-streams flag on clip subcommand - -map 0 preserves video + all audio tracks + subtitles - Default remains -map 0:v:0 for fast frame extraction