* Replace build tooling: Gulp/Mocha/Chai → node build.js + node:test
- Remove Gulp and all gulp-* plugins, chai, performance-now (9 devDeps → 1)
- Add terser as the only devDependency for minification
- Replace gulpfile.js with plain Node build.js using terser API
- Migrate tests to node:test + node:assert/strict, drop browser-compat fallbacks
- Update CI: actions/checkout@v4, actions/setup-node@v4, Node 20.x/22.x, push trigger, artifact sync check
* bump
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Co-authored-by: Teun Duynstee <teun@duynstee.com>