perf(wire): move LWDISPLAY toggle from CPU rebake to wire shader uniform

LWDISPLAY (Show Lineweight) flipping the toggle no longer triggers a full
retessellate. `render_style_for` always bakes the entity's resolved (layer-
inherited) lineweight, and the wire shader reads `Uniforms.lwdisplay_enable`
to either honour the per-vertex half_width or collapse the quad to a 1 px line.

Side effect: PDF export now uses the real lineweight regardless of LWDISPLAY,
matching AutoCAD's plot semantics (LWDISPLAY only affects screen render).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/app/commands.rs

@@ -4522,7 +4522,7 @@ impl H7CAD {
                     Ok(Some(v)) => {
                         self.push_undo_snapshot(i, "LWDISPLAY");
                         self.tabs[i].scene.document.header.lineweight_display = v;
-                        self.tabs[i].scene.bump_geometry();
+                        // No retessellate — the wire shader honours the flag via uniforms.
                         self.tabs[i].dirty = true;
                         self.command_line.push_output(&format!(
                             "LWDISPLAY {}",