my-skills maintenance — one entry for the aggregation repo

The single entry for every maintenance flow of this aggregation repo (flow vocabulary per GLOSSARY: vendor sync, consolidation, patch record, distribution chain, pending update). One discoverable skill, seven branches — each branch's procedure lives in a disclosed reference loaded only when that branch fires. This skill replaces consolidate-strays and my-skills-vendor-sync (retired at the map #18 migration).

Shared rules — every branch