Extend the rule beyond positional layout props to the text-reflow props
letterSpacing / wordSpacing / fontSize. Animating them reflows text and snaps
glyph positions to the pixel grid, so a slow ease-out tail micro-stutters
exactly like left/top — measured on a real composition, a slow letterSpacing
"settle" rendered 19/30 unique frames vs 30/30 for the transform-driven
motion in the same piece. They have no transform replacement (fix: settle via
scale or hold the value), and the snap happens during browser layout, upstream
of the canvas raster, so they are never html-in-canvas-exempt. width/height
stay excluded (legit animated uses — progress bars, reveals).
Restructure the finding's message/fixHint to compose per category (positional
-> x/y; reflow -> scale/hold; roundProps -> remove) instead of a two-branch
ternary. Skill guidance (gsap-transforms-and-perf.md) broadened: "layout
property" includes reflow; letterSpacing/fontSize named as the settle-trap.
Migrate the one surfaced positive: registry/components/vignette/demo.html
title settle letterSpacing -> a subtle scale settle (render-verified 20/20
unique frames, smooth). Blast radius across the registry was this one comp,
zero false positives.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Two surgical changes, both isolated to the catalog-previews flow:
1. `packages/studio/src/player/hooks/usePlaybackKeyboard.test.ts`
PR #842 changed `seek()` to take `(time, { keepPlaying: true })` for the
A/E shortcuts. The keyboard-layout tests added by #839 still asserted the
single-arg form. Both landed on main without cross-checking, so `main`
itself has been failing Test/Windows since. Update the two assertions
to match the new signature. Same fix Miguel already authored on
`feat/studio-preview-pasteboard-bg`.
2. `registry/components/vignette/demo.html`
The original demo captured a frame where the vignette was at its
weakest point — the effect was nearly invisible in the static preview
used by docs. Reworked the demo so:
- The backdrop is a layered "cinematic still" (warm key + teal rim +
dark falloff) and includes a centered subject ("moon"), so the
vignette has a focal point to frame.
- Vignette starts soft (size 70%, alpha 0.35) and ramps to a dramatic
cinematic vignette (size 26%, alpha 0.92) over 1.6s.
- Peak intensity holds across t≈3.0s, which is exactly where the
catalog script samples the thumbnail (`Math.min(3.0, duration*0.6)`
with duration=5).
- Breathing motion in t=3.4–5.2s gives the video loop visible life
without disturbing the still frame.
Pure-CSS radial darkening overlay that fills its positioned parent and
pulls focus toward the center. Shape, size, and color are exposed as
CSS custom properties (--vignette-shape, --vignette-size,
--vignette-edge, --vignette-color), so a GSAP timeline can animate any
of them — the snippet's header comment shows the pattern for fading
the vignette in.
The Components section currently has four entries; this fills the
cinematic-cinematography gap a video editor expects out of the box
without bundling any asset (the effect is a single radial-gradient).
Default z-index 90 sits below grain-overlay (100) so grain reads on
top of the darkened corners.
Catalog page, registry index, and nav are regenerated via
scripts/generate-catalog-pages.ts.
