Atomic params-to-commit operation. Affine resizing is centred across the
existing cut and held at its bottom; host thickness stays unchanged. Only
the occurrence's Representation/placement/dimensions change, never its type
maps, GlobalId, metadata or relationships. Refusals leave no overlay writes.
Atomic params-to-commit operation. Affine resizing is centred across the existing cut and held at its bottom; host thickness stays unchanged. Only the occurrence's Representation/placement/dimensions change, never its type maps, GlobalId, metadata or relationships. Refusals leave no overlay writes.