feat(pdf): searchable text layer with per-style subset font embedding

Real BT/Tj text objects ride alongside the vector outlines (Tr 3,
zero visual change): runs preserved at layout time, TTF styles embedded
as allsorts subsets with ToUnicode, width-matched Tm, clip-culled.
WireModel literals moved to ..Default::default() tails.

src/modules/annotate/radius_dim.rs

@@ -376,7 +376,9 @@ fn preview_wire(points: Vec<Vec3>) -> WireModel {
         plinegen: true,
         fill_tris: vec![],
         fill_tris_low: Vec::new(),
-    }
+    
+        ..Default::default()
+}
 }
 
 inventory::submit!(crate::command::CommandRegistration { names: &["DIMRADIUS"] });