forked from 1b-agent/fieldcraft-upstream
With symmetry, when the fundamental cell's two ends along another in-plane axis are alike (layout planes and surface mirror-symmetric), the cell is cut midway into the next block sheet and at its image; the low corner is meshed with its blocks, mirrored onto the high one, and the middle meshed with both cut faces fixed (#490). A plan cell's cut faces another cell's mesh covers are taken as given. corners: false opts out. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo