ADR-0087 exemption (no-migration-prescription): an enforcement change with no authorable surface behind it: no Zod schema, no metadata key, no spelling and no stored representation moves, so a stored `sys_permission_set` row needs no conversion and `objectstack migrate meta` has nothing to rewrite. What changes is whether an existing predicate is ENFORCED or silently dropped; the remedy for a newly-denied policy is to correct the column name in the policy, which is authoring, not migration — and the authoring-time detector for exactly that mistake is already shipped in `@objectstack/lint`.