The always-on crop lifted EVERY selected element's clip-path and restored
only what it could parse as a px inset — selecting an element with a
circle/polygon/percentage clip visually un-clipped it, and deselecting
deleted the authored clip outright.
readElementCropInsets is now tri-state (zeros = no clip, null = a clip
the tool can't represent): uneditable clips get no lift and no handles,
and the lift restores the pre-lift inline value verbatim unless a crop
gesture actually committed.