A nest drawing copied from the drawing library has to remember exactly which
revision it is a copy of, so later slices can tell when the library moved on
(D2b) and so a save can target the right drawing. `Drawing.Library` holds the
server key, id, revision and a snapshot of that revision's cut type, thickness,
material, grade, units, notes and package hash. It is immutable, so copies can
share it.
`DrawingDto.library` is additive and omitted when null. It is read leniently:
anything that cannot be trusted as a link drops the link with a reader warning
and the drawing still loads, because a nest must never fail to open over
provenance. Enum names are checked as single names since Enum.TryParse would
accept numbers and comma lists.
Copy paths: converter edits update drawings in place and so keep the link;
canonical engine copies carry it; split pieces are new geometry and get none.
Packages strip it so linking never changes a drawing's package bytes or hash.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
ajandClaude Opus 5.5
15654c0690