Give new drawings the standard visual styles

A new drawing carries the visual styles the reference's new drawing has
in its visual style dictionary. -VIEW sEttings Visual style offers them
(2dWireframe as "2D Wireframe") and a saved view starts with the 2D
Wireframe style.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/io/mod.rs

@@ -20,6 +20,7 @@ pub mod stl;
 pub mod xref;
 pub mod xref_model;
 pub mod linetypes;
+pub mod visual_styles;
 pub mod line_read;
 pub mod patterns;
 pub mod update_check;