retail-validatelisted

# retail-validate `seshat check` proves everything provable from committed text. `retail validate` proves the four things only a running database can show, on the MATERIALIZED rows (constitution Principle VIII). This skill runs it and maps each finding to the one place to fix it -- the live sibling of `retail-govern`. ## Scope boundary (read first) Invoke-and-interpret only. This skill runs the live checks and explains findings; it does NOT write or fix silver/gold SQL, does NOT call pbi-cli, and does NOT auto-loop. The live run needs a DB and is the user's call; you report and stop. ## Prerequisites - silver + gold are materialized for the table. - A reviewed `mappings/<table>/source-map.yaml` exists (the targets are derived from it -- table, PK, FK, measures). - The optional `db` extra is installed (`pipx inject seshat-bi psycopg2-binary`, or `pip install "seshat-bi[db]"`) and a DSN is configured (`DATABASE_URL` or the `ANALYTICS_DB_*` vars in the gitignored `.env`). Never commit a real DSN. ## Run it ``` retail validate --source-map mappings/<table>/source-map.yaml ``` The connection is host-agnostic (any Postgres: local / remote / DigitalOcean / other) and READ-ONLY (the session is opened read-only; the checks only SELECT). Exit is non-zero iff any check finds a defect. ## Read a finding Each is a `Finding(rule_id, severity, message, locator)`. Live findings are `ERROR` (proven defects -- a real PK duplicate, a real orphan, a real penny mismatch), unlike t