0010. OpenReel is the UX reference, with named deviations

Context

Designing an editor's gestures from scratch is a years-long project. OpenReel (MIT) has a complete timeline, inspector and action system with 115 action types and an undo history with gesture grouping.

Decision

Our action set maps onto OpenReel's feature set (docs/reference/parity.md), its enums are adopted verbatim so the two editors agree on names, and its history semantics are ported. Where its implementation is wrong we deviate and record it: trims recompute duration with speed, slide is the textbook operation, slip/slide/roll have inverses, consolidate and close-gap actually undo, keyframe removal keeps easing, edge trims and chroma key go through actions. Our additions: magnetic tracks, anchors, time references, locked expressions, bake-on-gesture, Layer interiors.

Consequences

• The eventual editor UI can copy OpenReel's gestures one to one.
• The player avoids OpenReel's playback mistakes (a container reopened per frame, whole-file audio decode before play, rate not applied to audio).