forked from 1b-agent/fieldcraft-upstream
Each cell (a body of the open design) gets its own method: structured hex where one fits (auto falls back to tet and says why), or tet. All go into one mesh. Cells on either side of a partition are joined: where their element faces match node for node the nodes are merged; otherwise (hex next to tet, or different divisions) the two partition faces get a set each and a dual mortar tie, the reported hex-tet transition. A 40 mm bar cut in half, one half hex, the other tet, stretches F L / (E A) to 1e-6. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo