The cutout prepass now bundles frames smallest first, so a larger frame's
round cutout can take a ring part or an earlier bundle as one insert through
the circle packer: a flange holds a washer that holds a smaller washer that
holds a slug. Chains stop at four parts deep. Lattice and NFP proposals never
take these inserts, since they could seat a part in a ring's bore.
Expansion and released demand recurse, so placed order cuts innermost first
at every level and an unplaced outer frame returns its whole chain to demand.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>