Surface Sweep: sheets carried from open curves and profiles along a path (#843)

Surface Sweep carries open curves and closed profile boundaries along a sketch path into surface bodies, with smooth walls along curved point paths. Adds the SurfaceSweep feature (format 18 note), the surface.sweep command, a dialog with Edit Feature support, and kernel and engine tests.

Part of #757.

crates/ui-egui/src/timeline.rs

@@ -15,6 +15,7 @@ pub(crate) fn icon_of(k: &FeatureKind) -> &'static str {
         FeatureKind::Unstitch { .. } => "unstitch",
         FeatureKind::ReverseNormal { .. } => "reverse_normal",
         FeatureKind::SurfaceRevolve { .. } => "surface_revolve",
+        FeatureKind::SurfaceSweep { .. } => "surface_sweep",
         FeatureKind::Revolve { .. } => "revolve",
         FeatureKind::Fillet { .. } => "fillet",
         FeatureKind::Chamfer { .. } => "chamfer",