forked from 1b-agent/fieldcraft-upstream
buckle-euler-pinned and buckle-euler-cantilever (hex20 columns, −0.18 % from Euler with Engesser's shear correction) and buckle-plate-square (a simply supported square plate, b/t = 100, −0.39 % from k = 4; the support and thickness choices in its README). ROADMAP and parity updated, docs/oracle.md regenerated. Co-Authored-By: Claude Opus 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo