/ssot-check — Fact-Copy Drift Auditor

Documentation-heavy repos repeat facts. An episode count lives in a README, then gets hand-copied into a media kit, a landing page, and a business plan. Someone updates the README. The copies drift. This skill finds those copies, records where the canonical value lives, and checks the copies against it on every run.

It complements /reconcile. Reconcile catches multi-session drift in state files. This skill catches fact-copy drift across documents: the same number or string living in several files, where exactly one file is allowed to be right.

Invocation: deliberately model-invocable — it belongs in pre-commit moments. No file is ever edited: fixes are proposed as diffs, never auto-applied. No repo being audited is ever modified — no pull, no rebase, no checkout, no commit, in this repo or a sibling.

Exactly one operation writes anything at all, and it is worth stating plainly rather than burying: git fetch in a sibling clone, which updates that clone's remote-tracking refs and FETCH_HEAD so a value can be compared against a live remote. It touches no working tree and no file. It is off by default and runs only on an explicit request from the user in that session. Absent that request, freshness comes from refs already on disk, or the fact is reported UNVERIFIED.

When to Use

• Discover mode: first run on a repo, or after adding a new doc surface (a media kit, a landing page, a pricing page)
• Check mode: before commits that touch docs, as a pre-commit habit, or any time a canonical number changed
• After a bulk find-and-replace, to confirm nothing was missed
• When a repo has a "grep for other files with the same number" rule that people forget to follow