Kernel: pole-free six-patch spheres; vendored truck-shapeops with robust meshing and nearest-parameter loop projection (sphere and box booleans work); least-squares sphere classification

Oracle: 25/29 (14 and 15 now match Fusion).

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

vendor/truck-shapeops/examples/punched-cube-shapeops.rs

@@ -0,0 +1,30 @@
+//! A punched cube generated by shape operator `AND`.
+
+use truck_modeling::*;
+
+fn main() {
+    let v = builder::vertex(Point3::origin());
+    let e = builder::tsweep(&v, Vector3::unit_x());
+    let f = builder::tsweep(&e, Vector3::unit_y());
+    let cube = builder::tsweep(&f, Vector3::unit_z());
+
+    let v = builder::vertex(Point3::new(0.5, 0.25, -0.5));
+    let w = builder::rsweep(&v, Point3::new(0.5, 0.5, 0.0), Vector3::unit_z(), Rad(7.0));
+    let f = builder::try_attach_plane(&[w]).unwrap();
+    let mut cylinder = builder::tsweep(&f, Vector3::unit_z() * 2.0);
+    cylinder.not();
+    let and = truck_shapeops::and(&cube, &cylinder, 0.05).unwrap();
+    and.edge_iter().for_each(|edge| {
+        let mut curve = edge.curve();
+        if let Curve::IntersectionCurve(inter) = &curve {
+            if matches! { inter.leader(), Leader::Polyline(_) } {
+                let flag = curve.to_bspline_leader(0.01, 0.1, 20);
+                println!("{flag}");
+            }
+        }
+        edge.set_curve(curve);
+    });
+
+    let json = serde_json::to_vec_pretty(&and).unwrap();
+    std::fs::write("punched-cube-shapeops.json", json).unwrap();
+}