Cut a span of TIME out of the whole video. Everything after it moves earlier by the same amount, on every lane at once - scenes, clips, captions and stickers stay in sync. A scene or voice clip the cut lands inside is SPLIT, so the material after the cut still plays. A scene piece the cut would leave under 100ms merges into the scene beside it; when no scene beside it has the footage, the cut widens to that scene's edge on every lane, and cut_start_ms / cut_end_ms report the range applied. Refuses when splitting a scene would pass the 100-scene cap (delete a scene first) and when a locked track holds clips after the cut (unlock it with lock_track). Not undoable.