my-skills-vendor-sync — resolve pending updates

A branch of my-skills-maintenance: follow its shared rules (repo anchor $REPO, propose-before-write, verify-then-report, GLOSSARY vocabulary, the finishing proposal) and its mandatory stray check already ran.

Bring every source's consolidated copies back to current — matching upstream except the documented patch records, with the pins recording the true base — and get the pending-update issue closed. The freshness check detects; this branch maintains. Coverage: edge-case inventory A1–A28.

Two invariants (ADR-0002) shape every step: patched files are never overwritten — upstream changes enter a patched file only through a merge that preserves the local patch — and files upstream removed are never deleted without an explicit call.

1. Read the pending-update issue and dry-run