Setup real browser test with jest-puppeteer
- Install jest-puppeteer and puppeteer dependencies
- Create browser test with HTTP server to serve test files
- Add test page HTML for browser testing
- Configure test to run only in production mode
- Test validates Prettier standalone bundle works in real browser
- Uses existing jest-light-runner for ESM compatibility
Co-authored-by: fisker <172584+fisker@users.noreply.github.com>
