The shrinker's `reorder` case is no longer red: its two seeds were a span
deciding whether anything was left over on a box length its own answer had
produced, which comes back a few bits off. `5ed9e87` in `/home/bob/repos/
iris-pr18` moves that boundary by `HOLDS_EPSILON_PX` of room instead of
softening the comparison, so the validity range stays exact where generated
seed 16 needs it.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>