ADR-0087 exemption (no-migration-prescription): Nothing an author writes moves: no `packages/spec` key, schema, export or config field is removed or renamed, and no stored metadata representation changes, so `objectstack migrate meta` has nothing to rewrite. What is refused is a predicate VALUE the engine's own filter admission already refuses whenever it is asked to run it; the refusal now arrives when the policy is authored. The new lint inputs are optional additions.