Add GitHub Actions workflow to auto-publish to npm on release

[identd113]

Summary

Adds a GitHub Actions workflow that automatically publishes to npm when a GitHub Release is published, or on demand via the Actions tab. Tests run first — publish is blocked if they fail.

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One-time setup required

Step 1 — Create an npm Automation token

1. Log in to npmjs.com
2. Go to Account → Access Tokens → Generate New Token
3. Choose Granular Access Token
4. Set the following:
   • Package: homebridge-og → permission: Read and write
   • Bypass 2FA: enabled (required for CI automation)
5. Copy the token — you won't see it again

Step 2 — Add the token as a GitHub secret

1. Go to github.com/OpenGarage/homebridge-og → Settings → Secrets and variables → Actions
2. Click New repository secret
   • Name: NPM_TOKEN
   • Value: the token from Step 1
3. Click Add secret

That's it. The workflow will now have publish access.

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How to publish a new version

1. Bump version in package.json, update CHANGELOG.md, commit and push
2. Go to GitHub → Releases → Draft a new release
3. Create a new tag matching the version (e.g. v3.2.1)
4. Add release notes, click Publish release
5. The workflow triggers automatically → tests run → publishes to npm

Alternatively, trigger it manually any time from Actions → npm publish → Run workflow.

Test plan

• NPM_TOKEN secret added (Steps 1–2 above)
• Publish a release → workflow runs, tests pass, package appears on npm
• Re-running on an already-published version fails with a clear error message
• Manual trigger via Actions tab works

🤖 Generated with Claude Code