Exact free-form profiles: geom Seg2 gains cubic Béziers and conics (rational quadratics: exact length, area, split, tangents); sketch ellipses, conics, text, fit splines and control splines up to degree 3 enter profiles as exact segments wherever a loop uses a whole segment, and the kernel builds them as B-spline / NURBS edges (an extruded ellipse is three faces with the exact volume)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/sketch/src/shape.rs

@@ -159,7 +159,7 @@ impl Sketch {
             CurveKind::Circle { c, r } => Some(Shape::Round { c: self.point(c)?, r, start: 0.0, sweep: TAU }),
             CurveKind::Arc { .. } => match self.segs(ci).into_iter().next()? {
                 Seg2::Arc { center, radius, start, sweep } => Some(Shape::Round { c: center, r: radius, start, sweep }),
-                Seg2::Line { .. } => None,
+                _ => None,
             },
             _ => None,
         }