ADR-0087 exemption (no-migration-prescription): Nothing authorable moves and nothing is renamed: no spec key, no config field, no stored-metadata shape, and no replacement spelling for anyone to adopt. The removed surfaces are one runtime function on `@objectstack/metadata/migrations`, its three own result/option/receipt types, and one member of a constant tuple — none of which appears in any authorable document, so `objectstack migrate meta` has nothing it could rewrite and a ledger entry would prescribe a rewrite that does not exist. The consumer-side action is a deletion, delivered by the compiler on the import and by the barrel tombstone beside it.