address review: restore matrixify_enable+mode_rows/mode_columns flag names

The hasMatrixifyChanges() check introduced matrixify_enable_vertical_layout /
matrixify_enable_horizontal_layout, but the rest of the codebase uses
matrixify_enable together with matrixify_mode_rows / matrixify_mode_columns.
Revert to the canonical flags so matrixify changes are actually detected,
and update the tests accordingly.