Meshing: start a face's boundary walk at a point the surface search finds (#882) (#1157)

When projecting a face's boundary loop onto its surface fails from an unhinted first point, the walk is retried once from the first point an unhinted search does find; a walk that succeeds is unchanged. A fillet strip on an extended surface now meshes, so the rim cut in the reported case builds in one boolean.

crates/engine/src/tests.rs

@@ -283,6 +283,7 @@ mod loft_spacing;
 mod mirror_planes;
 mod path_scope;
 mod primitive_points;
+mod rim_cut;
 mod robustness;
 mod robustness_goldens;
 mod spiral_join;