ADR-0087 exemption (already-registered): the pairs this change refuses are exactly the pairs AGGREGATE_FIELD_TYPE_COMPATIBILITY already refuses, and the table is not edited: every refused min / max pair is registered under protocol major 18 by the first id and every refused sum / avg pair by the second, each with its routes. This change makes the cube door read a relationship-path column's declaration on the object the path reaches, where it already read a base-object column's; it refuses a query shape, not a stored one, and no authorable key, export or stored row moves.