Export the current 3D view as 2D DXF with optional hidden lines (#1449)

Adds File > Export > Current View as DXF: the visible bodies projected from the current camera onto 2D LINE/LWPOLYLINE entities, with hidden edges omitted or dashed.

Co-authored-by: cronos <19868002+crono2250@users.noreply.github.com>
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

ROADMAP.md

@@ -66,6 +66,11 @@ pointer movement orbits without a mouse button, and vertical scrolling zooms. Ot
 retain their saved two-finger scroll preference; camera motion is available through
 `view.navigate` and modifier-aware `ui.move` automation.
 
+M11 precursor: File → Export Current View as DXF exports shown placed bodies from the current
+camera as a 2D millimetre drawing, with hidden edges omitted or dashed. Vector occlusion splits
+partly hidden edges and includes curved silhouettes. Curves are approximated; drawing sheets,
+annotations and exact projected curves remain deferred. See [view DXF](docs/view-dxf.md).
+
 ## Interactive modelling
 
 - New Body extrusion and face-offset previews show completed intermediate geometry while a