Check relationship_members for NULL scope_uuids

Confirms no orphaned NULL scope_uuids in relationship_members. A non-empty result means human participants are missing scope_uuid assignment or bot participants predate migration 016.

Zero rows returned. All participants have scope_uuids populated.

SELECT id, relationship_id, participant_a, participant_a_scope_uuid, participant_b, participant_b_scope_uuid FROM zoey_core.relationship_members WHERE participant_a_scope_uuid IS NULL OR participant_b_scope_uuid IS NULL ORDER BY id;