release: bump to v0.4.2 — React-compatible click + type/fill

Version bump and changelog for v0.4.2. Key changes:
- CDP mouse events for click/check/uncheck (React onClick compatibility)
- CDP key events for type/fill (React onChange compatibility)
- Fix click coordinate JS operator precedence bug
- Server realistic mode default for type/fill
- React 18 e2e test fixture

Signed binaries: codesign Developer ID Application: Rachit Pradhan (WWP9DLJ27P)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>