Why: Independent review found delegated account actions, stale resource policy, and role migration cutover gaps in the initial U4 implementation.
Evidence: Backend full SQLite suite passed; isolated PostgreSQL role and migration suite passed; independent final review found no remaining findings.
Impact: Enforces transactional system grants, current role snapshots, staged role import with v36 migration, and fail-closed activation.
Refs: feature/iam-u4-role-authority