Underlays are rasterised for the view's scale; DGN V7 strokes one pixel wide

A page shown small was drawn from its full-size raster and thin lines broke
up into dots. Once a zoom settles on another quarter-octave step, PDF, DWF
and DGN underlays are rasterised again near their size on screen (never
above the full-size raster), frames are requested until that happens, and
the adjusted-pixel memo is kept per raster size. V7 element weights no longer
widen strokes, matching V8 models.

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

src/scene/entity.rs

@@ -2419,7 +2419,7 @@ impl Scene {
                     } else {
                         self.paper_bg_color
                     };
-                    ImageModel::from_underlay(u, def, background)
+                    ImageModel::from_underlay(u, def, background, self.underlay_world_per_pixel)
                 }
                 _ => None,
             },