e420410f (D11) refuses a reference member whose CLR shape the cache cannot
walk; many:false needs CultRecordRef<T>. CultGeometryBuildRequest.DomainKey,
CultGeometrySelectedCutManifest.RequestKey and CultGeometryChunkArtifact.CutKey
were strings marked [CultReference], so registering the geometry catalog threw
and 7 geometry tests failed on main. All three are record keys of another
document, so the members become CultRecordRef<T> (the attribute is dropped, the
type declares the reference). The msgpack formatter writes a CultRecordRef as
its key string, so the wire bytes and the fingerprint inputs are unchanged.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>