Tests: the fill tests evaluate a face's (u, v) on its NURBS form

A face's domain and pcurves are on Face::parameters() (its NURBS form when it has one, the
record's documented contract); the general fill tests' quadrature and the pick-order and crown
comparisons evaluated Face::surface instead. A fill SMLib recognises as an analytic surface (the
240° window's G0 patch is the cylinder itself) then read its arc-length domain as angles: the
quadrature came out 4188.79 for the window's 418.879 (10 × 41.888 of angle against 4.189).

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

crates/kernel/src/fill.rs

@@ -1370,7 +1370,7 @@ mod tests {
         shuffled.swap(0, 1);
         let (b, _) = fill_rim(&open, &shuffled);
         let (ra, rb) = (record(&a), record(&b));
-        let (sa, sb) = (SurfaceEval::new(&ra.faces[0].surface).unwrap(), SurfaceEval::new(&rb.faces[0].surface).unwrap());
+        let (sa, sb) = (SurfaceEval::new(ra.faces[0].parameters()).unwrap(), SurfaceEval::new(rb.faces[0].parameters()).unwrap());
         let [[u0, u1], [v0, v1]] = ra.faces[0].domain;
         let mut gap = 0.0f64;
         for (x, y) in [(0.2, 0.3), (0.5, 0.5), (0.7, 0.9)] {
@@ -1586,7 +1586,7 @@ mod tests {
             mesh_is_clean(&full);
             // The middle of the loop's box moved by crown × its diagonal (the bump is 1 there).
             let (ra, rb) = (record(&plain), record(&full));
-            let (a, b) = (SurfaceEval::new(&ra.faces[0].surface).unwrap(), SurfaceEval::new(&rb.faces[0].surface).unwrap());
+            let (a, b) = (SurfaceEval::new(ra.faces[0].parameters()).unwrap(), SurfaceEval::new(rb.faces[0].parameters()).unwrap());
             let [[bu0, bu1], [bv0, bv1]] = ra.faces[0].domain;
             let (uc, vc) = ((bu0 + bu1) / 2.0, (bv0 + bv1) / 2.0);
             let size = (bu1 - bu0).hypot(bv1 - bv0);

crates/kernel/src/fill_general_tests.rs

@@ -43,7 +43,7 @@ impl Faces {
                         b::Loop::Vertex { .. } => None,
                     })
                     .collect();
-                (SurfaceEval::new(&f.surface).unwrap(), f.domain, polys)
+                (SurfaceEval::new(f.parameters()).unwrap(), f.domain, polys)
             })
             .collect();
         Faces { faces }