Promote fixes from the Plex client embed (layout, virtuallist, focus, reanimated, rendering)

[RuudBurger]

Batch of framework fixes developed against the Plex client's in-repo react-lightning embed and validated there before promotion. This is the full burst (63 commits, individual commits preserved) since we vendored main

Grouped by area:

Yoga / layout

• int16→int32 layout wire, percentage translate resolved against own size at readback, anchored-edge translate for right/bottom-docked nodes, logical start/end insets → yoga edges, border width fed into yoga, string aspectRatio parsing, dropped-flex reset to yoga defaults, synchronous text measurement + flushLayout/settled, same-parent insertChild treated as a move so reorders re-layout.

VirtualList

• drop estimatedItemSize (sizes come from overrideItemLayout or measurement), reveal driven off yoga-settled instead of timers, withhold rows until measured height settles, re-push cell cross-size after a data reset, skip stale visible indices after a sync shrink, viewport capped at stage edge + scrollSnapAlign, header/footer cross-axis pinned when width is definite, stop cross-size ratcheting off the parent cell.

Focus / spatial nav

• focus-when-ready + arrival-not-mount autoFocus + destinations-on-arrival, getLayout ref API + skipChildFocusScroll, skip empty focus groups, clamp cross-axis distance to the target span, expose focused state to function children, pointer-suppress aware focus-follow.

Reanimated

• bind animateStyle so composed animations play, composed sequence/repeat/delay on the node, honor caller easing in withTiming, infer hook deps by tracking shared-value reads, skip no-op style animations, partial style pushes so static flex props survive.

Rendering / misc

• opt-in view flattening (flattenLayoutViews) with placeholder fold-through, rounded clipping via stencil clipRadius, withhold paint until first layout, Image array-style flattening + border shaders on live nodes, key-event normalization + held-key auto-repeat, font-atlas url resolution before the inlined worker, drop unresolvable css keyword colors, CanvasRoot export for react-dom-free mount, glyph fallback advance measurement, @lightningjs/renderer 3.1.1 bump.

Commits are individually scoped and messaged; each applies cleanly on main