forked from 1b-agent/fieldcraft-upstream
split_by_plane gives one body per side, which may hold several shells when the side falls apart; every lump is now its own cell (B/a1, B/a2), at every cut, as the partition docs promise. Co-Authored-By: Claude Opus 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo