ADR-0087 exemption (no-migration-prescription): Nothing authorable moves: no spec key, export, config field or stored metadata changes spelling or shape, `packages/spec` is untouched, and `objectstack migrate meta` has nothing to rewrite. What is retired is the NAME of a best-effort supervision file that `os serve` writes under the ObjectStack home — a path on disk, not a metadata surface the ledger can project into `spec-changes.json` or the generated upgrade guide. The affected party is an out-of-tree supervisor that opens that path, and the one action it takes is deleting a single stale file; there is no authored artifact for a metadata upgrader to rewrite, and no ledger entry could reach the party that is affected.