Dialog labels show in full: the label column grows to its longest label (up to 150 px, then wraps) instead of cutting labels off. Feature previews that remove material (Hole, pockets) show the cut's new faces through the body in the cut colour, so the hole is seen from any side

Fixes #18

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

crates/ui-egui/src/preview.rs

@@ -270,12 +270,19 @@ pub fn build(before: &ModelState, after: &ModelState, c: Colors) -> Built {
         }
         let nf = am.tri_face.iter().max().map_or(0, |m| *m as usize + 1);
         let added: Vec<bool> = (0..nf).map(|f| old.as_ref().is_none_or(|bm| face_is_new(&am, f, bm))).collect();
+        // Material removed from a body (a hole, a pocket): its new faces also show through the
+        // body in the cut colour, so the cut is seen from any side.
+        let cut = old.as_ref().is_some_and(|bm| am.measure().volume < bm.measure().volume - 1e-6);
         for (t, f) in am.triangles.iter().zip(&am.tri_face) {
-            let col = if added.get(*f as usize).copied().unwrap_or(true) { c.added } else { c.body };
+            let new = added.get(*f as usize).copied().unwrap_or(true);
+            let col = if new { c.added } else { c.body };
             for k in t {
                 let i = *k as usize;
                 if let (Some(p), Some(n)) = (am.positions.get(i), am.normals.get(i)) {
                     sc.tri(p.to_f32(), n.to_f32(), col);
+                    if new && cut {
+                        sc.xray_tri(p.to_f32(), n.to_f32(), c.removed);
+                    }
                 }
             }
         }
@@ -364,6 +371,19 @@ mod tests {
         bytes.chunks(stride).filter(|v| v.get(24..28) == Some(&col[..])).count()
     }
 
+    #[test]
+    fn a_hole_shows_its_cut_through_the_body() {
+        let mut s = solvecraft_engine::Session::default();
+        s.execute("solid.box", &json!({"length": 40, "width": 30, "height": 20})).unwrap();
+        let p = s.preview(&[("solid.hole".to_string(), json!({"position": [20, 15, 20], "diameter": 5, "depth": 10}))]).unwrap();
+        let b = build(&p.before, &p.after, colors());
+        // The hole's walls are drawn see-through in the cut colour (seen from any side).
+        assert!(count(&b.scene.xray, 28, colors().removed) > 0);
+        // A feature that only adds material shows no cut.
+        let p = s.preview(&[("solid.box".to_string(), json!({"length": 10, "width": 10, "height": 30, "operation": "join"}))]).unwrap();
+        assert_eq!(count(&build(&p.before, &p.after, colors()).scene.xray, 28, colors().removed), 0);
+    }
+
     fn plate() -> Session {
         let mut s = Session::default();
         for (id, p) in [