`mov` ran ten times across the suite and never once recursed: `Rect`,
`Image` and `()` are the only widgets claiming `OnResize::Scale` and all
three are childless, so the walk that remaps a subtree's children -- the
thing `Remap` exists for -- had no coverage at all.
`Stretchy` is a test widget that claims `Scale` and holds a child, which
is the shape no shipped container has. Removing the recursion leaves its
child behind at the old box and the test says so.
iris-ai