- Add GitHub Actions CI for cross-platform testing (ubuntu/windows/macos × node 18/20/22)
- Add release workflow that auto-creates GitHub Releases and publishes to npm on tag push
- Add CONTRIBUTING.md with branching strategy (maintainers direct commit, contributors PR)
- Add MAINTAINERS.md with release workflows and recovery procedures
- Add PR template for contributors
Closes#221
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>