Check A - U_legacy Object-Only Recheck

Verdict: U_LEGACY_OBJECT_ONLY_ACCEPTED

U_legacy_object is limited to PostgreSQL objects addressable through PG object identity. Roles/principals and DOT/scheduler/trigger/external vectors are excluded. The object both-EXCEPT and uniform-end-state predicates apply only to this object universe. G-U-LEGACY-OBJECT-ONLY is concrete and fail-closed.

No remaining Check-A blocker.