Automate mainline next publish and patch bump PR flow

[anandpant]

Summary

• switch package publish workflow to fully automatic CI/CD on push to main (no manual trigger)
• publish to GitHub Packages using npm dist-tag next
• enforce patch-only version scheme 0.0.x for this flow
• set package baseline version to 0.0.1
• after publish, auto-open a PR bumping package.json to the next patch version (0.0.x -> 0.0.(x+1))
• keep release gated to merged PR commits only (no direct push publishing)

Notes

• Workflow: .github/workflows/publish-package.yml
• Version baseline update: package.json
• README updated with release automation behavior

Validation

• bun run format
• bun run check
• bun run typecheck
• bun test
• bun run build