CI patterns

• Gate (every push/PR): docref check. Blocks merging docs whose refs are broken, and code changes that strand same-repo refs.
• Mechanical sync (pre-commit or bot): docref refresh keeps snippet bodies current; as a scheduled bot it opens a PR whose diff is itself the review surface.
• Cross-repo watch (scheduled): docref update --check nightly in the docs repository. The morning after a referenced repository changes an anchored region, the job goes red and names the affected pages. Advancing the pin is then a normal PR via docref update.

The gate is what makes divergence hard rather than merely visible; the editor integration only makes it cheap to fix early.