Two leftovers from the UCS grid work:
- The coloured X/Y/Z axis lines (draw_axes) were drawn at the world
origin along world axes; they now run through the UCS origin along the
UCS axes, matching the grid lines.
- Grid snap rounded the cursor on the world XYZ lattice; it now rounds in
the UCS grid frame (to-UCS, round, back-to-world) so it lands on the
grid the user sees. The UCS origin (wire space) + rotation reach the
snapper via DocumentTab::ucs_grid_basis; identity outside model space.
Co-Authored-By: Claude Opus 4.8 <[email protected]>