Review follow-ups on the expanded keyframe lanes.
Writer:
- `onMoveKeyframe`'s flat-tween boundary branch answered `true` the moment it
dispatched update-meta, so a rejected write left the diamond parked at its drop
position. `observeGsapMutation` now resolves to whether the mutation landed and
the boundary branch returns it, matching the other branches.
- "Delete All Keyframes" cleared only the first keyframed tween on the layer, so
a layer with position AND opacity keyframes kept half of them. It now walks
every keyframed tween, serially, through the clicked element's selection.
- The post-convert lookup in `commitFlatViaKeyframes` matched by target selector,
which picks an arbitrary tween when a target carries several. Match by id first.
Interaction and a11y:
- A rejected retime whose commit settled after a newer drag reverted the
selection to its own source keyframe, undoing a retime the user could see. The
revert now only runs while it is still the lane's latest gesture.
- Diamonds key on the authored identity instead of index plus rendered clip-%, so
a neighbour's retime no longer remounts the button mid-drag.
- The disclosure caret gets `aria-controls` on an always-mounted lanes container,
and both it and the property-group toggle grow to the 24x24 WCAG 2.2 minimum.
- `LayerDisclosureRow` takes the same adaptive `columnWidth` as its sibling lane
rows instead of hardcoding LABEL_COL_W over the canvas.
Test locks:
- The timeline callbacks harness resolves a DISTINCT selection per element, so
the clicked-element writes are actually pinned; three assertions that passed
either way now name the clicked element's selection.
- New: null-selection aborts every mutation, delete-all covers both tweens, a
rejected boundary retime reports `false`, and a stale revert leaves selection.
- The playhead-percentage assertion checks 25, not `expect.any(Number)` (which
also accepts NaN); ease segments assert their label ORDER, not just that the
three curves differ; the collapsed-diamond callback asserts the whole target.
- Dropped a duplicate `selection override` describe left by a rebase.
Miguel Angel Simon Sierra
8470b88aa1