Living design note per the docs/dev-notes convention: problem, key
facts (library-per-path reuse, SKIP_SAVE last-used-property retention,
IfcDocumentReference conventions, link matrix math), per-feature design
decisions, commit map, and open test items.
Generated with the assistance of an AI coding tool.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Ryan Schultz