When line.thickness != 0, renders 4 NaN-separated wire segments
(bottom, top, left wall, right wall) using TruckObject::Lines.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Entities carrying a non-standard extrusion normal (normal ≠ (0,0,1)) were
rendered flat in the XY plane. The DXF arbitrary-axis algorithm is now
implemented in scene::transform::{ocs_axes, ocs_point_to_wcs} and applied
during tessellation of Arc, Circle, and Line so they render correctly on
tilted planes in 3D DXF files.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>