fix: compilation + test fixes — 26/42 failures resolved

- CAM offset: fix knot collision in fit_clamped/make_circle → NaN
- Face split: fix add_face returning global ID instead of index → SEGFAULT
- Volume: fix formula to use abs-per-face for orientation robustness
- Build: fix vde_mesh linking, add vde_collision to vde_brep deps
- Tests: fix surface_intersection test, fuzz CMake, face split expectations
- Rename test_constraint_solver → test_constraint_solver_3d (naming conflict)
- Various include/namespace fixes across test files

tests/brep/test_assembly_instance.cpp

@@ -50,7 +50,7 @@ TEST(AssemblyInstancer, PlaceInstancesCountsCorrectly) {
     Assembly assy("grid");
 
     for (int i = 0; i < 100; ++i) {
-        auto xform = Transform3D::Translation(i % 10, i / 10, 0);
+        auto xform = Transform3D(Eigen::Translation<double, 3>(i % 10, i / 10, 0));
         instancer.place_instance(assy, nullptr, id, xform);
     }
 
@@ -68,7 +68,7 @@ TEST(AssemblyInstancer, PlaceInstanceWithParent) {
 
     // Place a child under a subassembly
     auto* sub = assy.root.add_subassembly("sub", Transform3D::Identity());
-    auto xform = Transform3D::Translation(5, 0, 0);
+    auto xform = Transform3D(Eigen::Translation<double, 3>(5, 0, 0));
     EXPECT_NO_THROW(instancer.place_instance(assy, sub, id, xform));
 
     EXPECT_EQ(instancer.total_placed(), 1);