space_parent_mismatch· reason_code· applies to event_envelope, state_resolutionThe expected_parent_space_id declared by an ak.space.parent payload and the parent_space_id stored in that Space's space_parent register are not byte-equal. Both are always present -- the payload member is required and the register is written for every Space by the ak.space.create genesis write -- so this is a two-valued equality, not the three-valued stored_field_matches_payload the directed-invite slot needs. Reducer MUST reject with zero writes (zh/models/realm-and-space.md section 3.5).