Closes the empty-pipe class Stage 2 (v0.4.15) couldn't reach: tessellated
MEP whose IfcCartesianPointList3D embeds huge world coords directly
(post-transform / georeferenced files). Faceset parses in f64 + bbox-min
rebase; bake loop applies the rebase through an f64 per-fragment anchor
and the existing global shift. Synthetic IfcPolygonalFaceSet at 5e7 m:
intact via point_cloud() / meshes(). Near-origin and Stage-1+2 cases
unchanged.