Chrome trace showed ~0.5s self-time in _isHighwayVisible (offsetParent
read every rAF frame forces style/layout recalc) and ~1.5s in the v3
player-chrome loop (matches(':hover') per frame, unconditional
textContent/width writes at 6 Hz -> ~1800 layout passes in 63s).
- highway.js: sample offsetParent every 10th frame, cached in between;
fresh sample forced on init/canvas-replace/resize/override-clear.
- player-chrome.js: hover tracked via mouseenter/mouseleave; Up-Next
refs cached, text written only on change (eta coarsened to 1s steps
beyond 10s), progress bar moved from width to scaleX (compositor-only).
- v3.css: bar fill uses transform-origin:left + scaleX transition.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
