- Member update_member: on_missing :unrelate → :ignore (no unlink when :user omitted)
- Test: normal_user update linked member without :user keeps link
- Doc: unlink only explicit (user: nil), admin-only; Actor.admin?(nil) note
- Check: defense-in-depth for "user" string key
- Forbid on :user argument presence (not value) to block unlink via nil/empty
- Defensive nil actor handling; policy restricted to create/update only
- Test: Ash.load with actor; test non-admin cannot unlink via user: nil
- Docs: unlink behaviour and policy split
- Policy tests: use Fixtures where applicable; create_custom_field() fix in custom_field_value.
- Replace unused actor with _actor, remove unused alias Accounts in policy tests.
- profile_navigation_test: disable Credo for intentional TODO comment.
