Found by the cross-format fuzz leg. importDocx baked the resolved cell
chain in as direct formatting even where it equals what an unset attr
already renders (0/0 spacing; single line height over a single default) —
every re-imported own file grew spacing attrs on every cell paragraph.
And a numbering level kept the first list kind it saw, so a nested bullet
list beside a nested ordered one came back ordered; a kind conflict now
forks its own numbering reference, as the ODT side mints a list style.