An additive HostApi::solid_operation builds cadkernel primitives and applies
rigid transforms, verifying each result lifts back losslessly and refusing a
payload it cannot lift. Exposed as doc.solids in Python; Solid3D, Body and
Region are mapped read-only with the opaque payload preserved. The lifecycle
test passes through the real runner with analytic volumes and exact extents as
oracles, DWG and DXF reopen with re-edit, and undo restores exactly.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
OCS already creates, transforms and combines bodies through cadkernel, and
solid_to_sat / kernel_acis_body verify each result lifts back losslessly.
Two ignored spike tests measure volumes and DWG/DXF round trips. The
blocker is an operation channel, not geometry; the note recommends an
additive solid_operation host method and phases the work.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>