check-drift — no change is done until every coupled artifact moves with it

A change is silent drift until the same PR updates all its coupled artifacts. This skill turns that discipline into a check.

Procedure

1. Load the map: read .skills/change-map.yaml at the repo root. It lists

couplings, each with a trigger, an optional ssot, a must_update list, and optional revalidate steps.

1. Diff the change: get the working-tree / PR diff (changed files).
2. Match couplings: for each coupling whose ssot or trigger-owned file

appears in the diff, treat it as fired.

1. Report gaps: for each fired coupling, list every must_update path that

is NOT in the diff. That list is the drift. Be specific — path by path.

1. Delegate the mechanizable half: if the repo has a consistency linter

(e.g. scripts/check-consistency.sh), run it and fold its output in — it catches the grep-able stale refs; this skill catches the rest.

1. Flag revalidation: if a fired coupling has revalidate steps (a golden

lane, a rebuild), remind the user to run them — a moved file can still be semantically stale.

1. Self-check: verify the tools/agent-skills/ pointer + index block exist

and match across the project's docs (this skill's own wiring is a coupling).

Output

A short verdict: OK — all couplings satisfied, or a per-coupling list of missing artifacts. No prose padding. If nothing in the diff matches any coupling, say so plainly rather than inventing findings.

Extending

When a new mechanically-checkable coupling appears, add it to .skills/change-map.yaml (not to this body) — that is how the "automat" grows without editing the skill.