- footage.check: background footage check after File > Open (Progress panel), not an undo step
- timeline: track-matte / parent menus built only while open (was O(n^2) per frame);
expression-row lookup per layer; panels hold Arc<Comp> snapshots instead of deep clones
- Project panel: virtualised vertical scrolling, selection reveal, thumbnails rendered off
the UI thread
- effectcraft-cli bench --ops (engine::perf + ui-egui::bench)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>