chore(ci): add release and promote GitHub workflows

[christso]

Summary

• Release workflow (release.yml): Triggers on v* tag push. Builds, publishes all packages to npm next channel, then creates a GitHub Release with auto-generated release notes.
• Promote workflow (promote.yml): Manual dispatch. Promotes a version from next to latest dist-tag. Accepts optional version input (defaults to package.json version).

Both workflows use NPM_TOKEN secret for npm auth (generated dynamically as .npmrc — not committed).

Setup required

1. Add NPM_TOKEN to GitHub repo secrets (Settings > Secrets > Actions)
   • Generate from npmjs.com: Access Tokens > Generate New Token > Automation

Release flow

bun run release          # bumps version, creates v* tag, pushes
# → release.yml triggers automatically → publishes to npm next
# verify on npm, then:
gh workflow run promote.yml   # or use Actions UI to promote to latest

Test plan

• Add NPM_TOKEN secret to the repo
• Run bun run release to create a tag and verify the release workflow triggers
• Verify packages appear on npm with next tag
• Run promote workflow from Actions UI and verify latest tag updates

🤖 Generated with Claude Code

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