GameCult.Geometry no longer carries vector or rectangle values. CultCircle and
CultSphere hold float2/float3, the isosurface and surface-nets extractors take
float3 origin, and the per-call conversion to float3 is gone. Their MessagePack
bytes are unchanged (pinned against the pre-collapse encodings), now produced
by CultMathResolver through the default CultCache options.
This is a breaking change to the GameCult.Geometry public API.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
