Measures the current build's cold load, open+render, and pan/zoom FPS
(1x/4x/6x CPU-throttle sweep) for both editors, writing
tests/test-results/perf-*.json. Track-only: asserts only that the app booted
and the document opened — no perf thresholds, so it never gates CI.
Runs on a new Chromium `perf` Playwright project (CDP throttling; pcbnew needs
V8 anyway) via `npm run test:perf`, and is wired into wasm-build.yml as a
continue-on-error step so the numbers are captured/uploaded without flaking the
gate. Reuses the existing fixtures, ready-signal, fs-inject, and board-ready
helpers; FPS counter is cancel-able so a throttle sweep on one page doesn't
accumulate rAF loops.
.gitignore: ignore /benchmark-builds/ (disposable prebuilt-WASM + standalone
harness bundle used to reproduce the native-vs-JS-EH comparison locally).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>