cslotboom/limitstates ? reverse-engineered prompt

Build me a Python library for structural engineering design called limitstates.

I want it to let me define structural members, materials, and sections, then run design checks against code based standards, starting with Canadian steel and wood design. It should have a simple, clean API so someone can create a beam, attach a material and section, and ask for things like moment or shear capacity. Include the core pieces for units, generic structural objects, design code specific classes, and a small analysis layer where it makes sense.

Please make it usable as a real package, with a few working examples, basic tests, and clear documentation friendly code. If you need to look up current code details or standard names online, feel free to do that. Keep the design open enough that later I can add more countries, materials, and concrete support without rewriting everything.