feat: add UI Build Artifacts Check workflow

[agiannelli-auth0]

Description

PRs that change ui/src/ or universal-components/src/ sometimes land without the corresponding built artifacts in main/ui/, because contributors aren't always aware that copy-build.sh needs to be run and committed.

This adds a GitHub Actions workflow that fails the PR if source changes are detected without matching artifact updates, and prints the exact command to fix it.

What the check does:

• If ui/src/** changed but main/ui/auth0-docs-ui-* didn't → fail
• If universal-components/src/** changed but main/ui/universal-components/** didn't → fail
• Skips on draft PRs
• Prints an ::error:: annotation with the command to run (cd ui && npm run copy:build or cd universal-components && pnpm run copy:assets)

In addition, build scripts (copy-build.sh, build-all.sh) now automatically bump the patch version in package.json before each build, unless the version was already manually changed since the last commit — preventing accidental double-bumps when a contributor intentionally sets a minor or major version.

References

Internal optimization

Testing

Checklist

• I've read and followed CONTRIBUTING.md.
• I've tested the site build for this change locally.
• I've made appropriate docs updates for any code or config changes.
• I've coordinated with the Product Docs and/or Docs Management team about non-trivial changes.

[github-actions]

Full Github Actions output