Post-release improvements:
- CI: GitHub Actions on Node 20/22/24
- CI: npm Trusted Publishing (OIDC, no token)
- Docs: shields.io badges, contributing section, sponsor link
- Docs: funding config (GitHub Sponsors + Tidelift)
- Fix: doc-reporter Node 20 compatibility (.ts → .cjs)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>