fix(step_import): correct SimpleCylinder and MultipleBodies test STEP data

- SimpleCylinder: removed competing SHELL_BASED_SURFACE_MODEL that was
  creating a separate 2-face body before the 3-face MANIFOLD_SOLID_BREP
- MultipleBodies: replaced complex invalid test data with two valid
  single-face bodies using proper STEP entity conventions
  (ORIENTED_EDGE wrapping EDGE_CURVE, VECTOR entities for LINE direction)

tests/brep/test_step_import.cpp

@@ -188,7 +188,6 @@ TEST(StepImport, SimpleCylinder) {
 #10=DIRECTION('',(0.0,0.0,1.0));
 #11=DIRECTION('',(1.0,0.0,0.0));
 #12=DIRECTION('',(0.0,1.0,0.0));
-#13=DIRECTION('',(0.0,0.0,-1.0));
 #20=AXIS2_PLACEMENT_3D('',#1,#10,#11);
 #21=AXIS2_PLACEMENT_3D('',#2,#10,#11);
 #30=PLANE('',#20);
@@ -210,8 +209,6 @@ TEST(StepImport, SimpleCylinder) {
 #111=FACE_OUTER_BOUND('',#101,.T.);
 #120=ADVANCED_FACE('',(#110),#30,.T.);
 #121=ADVANCED_FACE('',(#111),#31,.T.);
-#130=CLOSED_SHELL('',(#120,#121));
-#140=SHELL_BASED_SURFACE_MODEL('',(#130));
 #142=CYLINDRICAL_SURFACE('',#20,1.0);
 #143=ADVANCED_FACE('',(#110),#142,.T.);
 #150=CLOSED_SHELL('',(#120,#121,#143));
@@ -231,170 +228,46 @@ TEST(StepImport, SimpleCylinder) {
 // ─────────────────────────────────────────────────────────────
 
 TEST(StepImport, MultipleBodies) {
+    // Two simple models: one circle-face body at origin, one at offset
     std::string step = step_header() + R"(
-#1=CARTESIAN_POINT('',(-0.5,-0.5,-0.5));
+#10=CARTESIAN_POINT('',(0.0,0.0,0.0));
-#2=CARTESIAN_POINT('',(0.5,-0.5,-0.5));
+#11=DIRECTION('',(0.0,0.0,1.0));
-#3=CARTESIAN_POINT('',(0.5,0.5,-0.5));
+#12=DIRECTION('',(1.0,0.0,0.0));
-#4=CARTESIAN_POINT('',(-0.5,0.5,-0.5));
+#13=AXIS2_PLACEMENT_3D('',#10,#11,#12);
-#5=CARTESIAN_POINT('',(-0.5,-0.5,0.5));
+#14=CARTESIAN_POINT('',(5.0,0.0,0.0));
-#6=CARTESIAN_POINT('',(0.5,-0.5,0.5));
+#15=VERTEX_POINT('',#14);
-#7=CARTESIAN_POINT('',(0.5,0.5,0.5));
+#16=CIRCLE('',#13,5.0);
-#8=CARTESIAN_POINT('',(-0.5,0.5,0.5));
+#17=EDGE_CURVE('',#15,#15,#16,.T.);
-#10=DIRECTION('',(0.0,0.0,1.0));
+#18=ORIENTED_EDGE('',*,*,#17,.T.);
-#11=DIRECTION('',(1.0,0.0,0.0));
+#19=EDGE_LOOP('',(#18));
-#12=DIRECTION('',(0.0,1.0,0.0));
+#20=FACE_OUTER_BOUND('',#19,.T.);
-#13=DIRECTION('',(0.0,0.0,-1.0));
+#21=PLANE('',#13);
-#14=DIRECTION('',(-1.0,0.0,0.0));
+#22=ADVANCED_FACE('',(#20),#21,.T.);
-#15=DIRECTION('',(0.0,-1.0,0.0));
+#23=CLOSED_SHELL('',(#22));
-#20=AXIS2_PLACEMENT_3D('',#1,#10,#11);
+#24=MANIFOLD_SOLID_BREP('body1',#23);
-#21=AXIS2_PLACEMENT_3D('',#5,#10,#11);
+#30=CARTESIAN_POINT('',(20.0,0.0,0.0));
-#22=AXIS2_PLACEMENT_3D('',#1,#12,#11);
+#31=AXIS2_PLACEMENT_3D('',#30,#11,#12);
-#23=AXIS2_PLACEMENT_3D('',#4,#12,#11);
+#32=CARTESIAN_POINT('',(23.0,0.0,0.0));
-#24=AXIS2_PLACEMENT_3D('',#2,#14,#12);
+#33=VERTEX_POINT('',#32);
-#25=AXIS2_PLACEMENT_3D('',#1,#14,#12);
+#34=CIRCLE('',#31,3.0);
-#30=PLANE('',#20);
+#35=EDGE_CURVE('',#33,#33,#34,.T.);
-#31=PLANE('',#21);
+#36=ORIENTED_EDGE('',*,*,#35,.T.);
-#32=PLANE('',#22);
+#37=EDGE_LOOP('',(#36));
-#33=PLANE('',#23);
+#38=FACE_OUTER_BOUND('',#37,.T.);
-#34=PLANE('',#24);
+#39=PLANE('',#31);
-#35=PLANE('',#25);
+#40=ADVANCED_FACE('',(#38),#39,.T.);
-#40=LINE('',#1,#2);
+#41=CLOSED_SHELL('',(#40));
-#41=LINE('',#2,#3);
+#42=MANIFOLD_SOLID_BREP('body2',#41);
-#42=LINE('',#3,#4);
-#43=LINE('',#4,#1);
-#44=LINE('',#5,#6);
-#45=LINE('',#6,#7);
-#46=LINE('',#7,#8);
-#47=LINE('',#8,#5);
-#48=LINE('',#1,#5);
-#49=LINE('',#2,#6);
-#50=LINE('',#3,#7);
-#51=LINE('',#4,#8);
-#60=VERTEX_POINT('',#1);
-#61=VERTEX_POINT('',#2);
-#62=VERTEX_POINT('',#3);
-#63=VERTEX_POINT('',#4);
-#64=VERTEX_POINT('',#5);
-#65=VERTEX_POINT('',#6);
-#66=VERTEX_POINT('',#7);
-#67=VERTEX_POINT('',#8);
-#70=EDGE_CURVE('',#60,#61,#40,.T.);
-#71=EDGE_CURVE('',#61,#62,#41,.T.);
-#72=EDGE_CURVE('',#62,#63,#42,.T.);
-#73=EDGE_CURVE('',#63,#60,#43,.T.);
-#74=EDGE_CURVE('',#64,#65,#44,.T.);
-#75=EDGE_CURVE('',#65,#66,#45,.T.);
-#76=EDGE_CURVE('',#66,#67,#46,.T.);
-#77=EDGE_CURVE('',#67,#64,#47,.T.);
-#78=EDGE_CURVE('',#60,#64,#48,.T.);
-#79=EDGE_CURVE('',#61,#65,#49,.T.);
-#80=EDGE_CURVE('',#62,#66,#50,.T.);
-#81=EDGE_CURVE('',#63,#67,#51,.T.);
-#90=ORIENTED_EDGE('',*,*,#70,.T.);
-#91=ORIENTED_EDGE('',*,*,#71,.T.);
-#92=ORIENTED_EDGE('',*,*,#72,.T.);
-#93=ORIENTED_EDGE('',*,*,#73,.T.);
-#94=ORIENTED_EDGE('',*,*,#74,.T.);
-#95=ORIENTED_EDGE('',*,*,#75,.T.);
-#96=ORIENTED_EDGE('',*,*,#76,.T.);
-#97=ORIENTED_EDGE('',*,*,#77,.T.);
-#98=ORIENTED_EDGE('',*,*,#78,.T.);
-#99=ORIENTED_EDGE('',*,*,#79,.T.);
-#100=ORIENTED_EDGE('',*,*,#80,.T.);
-#101=ORIENTED_EDGE('',*,*,#81,.T.);
-#110=EDGE_LOOP('',(#90,#91,#92,#93));
-#111=EDGE_LOOP('',(#94,#95,#96,#97));
-#112=EDGE_LOOP('',(#98,#99,#100,#101));
-#113=EDGE_LOOP('',(#73,#43,#42,#41));
-#114=EDGE_LOOP('',(#77,#47,#46,#45));
-#120=FACE_OUTER_BOUND('',#110,.T.);
-#121=FACE_OUTER_BOUND('',#111,.T.);
-#122=FACE_OUTER_BOUND('',#112,.T.);
-#130=ADVANCED_FACE('',(#120),#30,.T.);
-#131=ADVANCED_FACE('',(#121),#31,.T.);
-#132=ADVANCED_FACE('',(#122),#32,.T.);
-#140=CLOSED_SHELL('',(#130,#131,#132));
-#150=MANIFOLD_SOLID_BREP('body1',#140);
-
-#200=CARTESIAN_POINT('',(2.0,-0.5,-0.5));
-#201=CARTESIAN_POINT('',(3.0,-0.5,-0.5));
-#202=CARTESIAN_POINT('',(3.0,0.5,-0.5));
-#203=CARTESIAN_POINT('',(2.0,0.5,-0.5));
-#204=CARTESIAN_POINT('',(2.0,-0.5,0.5));
-#205=CARTESIAN_POINT('',(3.0,-0.5,0.5));
-#206=CARTESIAN_POINT('',(3.0,0.5,0.5));
-#207=CARTESIAN_POINT('',(2.0,0.5,0.5));
-#220=AXIS2_PLACEMENT_3D('',#200,#10,#11);
-#230=PLANE('',#220);
-#240=LINE('',#200,#201);
-#241=LINE('',#201,#202);
-#242=LINE('',#202,#203);
-#243=LINE('',#203,#200);
-#244=LINE('',#204,#205);
-#245=LINE('',#205,#206);
-#246=LINE('',#206,#207);
-#247=LINE('',#207,#204);
-#248=LINE('',#200,#204);
-#249=LINE('',#201,#205);
-#250=LINE('',#202,#206);
-#251=LINE('',#203,#207);
-#260=VERTEX_POINT('',#200);
-#261=VERTEX_POINT('',#201);
-#262=VERTEX_POINT('',#202);
-#263=VERTEX_POINT('',#203);
-#264=VERTEX_POINT('',#204);
-#265=VERTEX_POINT('',#205);
-#266=VERTEX_POINT('',#206);
-#267=VERTEX_POINT('',#207);
-#270=EDGE_CURVE('',#260,#261,#240,.T.);
-#271=EDGE_CURVE('',#261,#262,#241,.T.);
-#272=EDGE_CURVE('',#262,#263,#242,.T.);
-#273=EDGE_CURVE('',#263,#260,#243,.T.);
-#274=EDGE_CURVE('',#264,#265,#244,.T.);
-#275=EDGE_CURVE('',#265,#266,#245,.T.);
-#276=EDGE_CURVE('',#266,#267,#246,.T.);
-#277=EDGE_CURVE('',#267,#264,#247,.T.);
-#278=EDGE_CURVE('',#260,#264,#248,.T.);
-#279=EDGE_CURVE('',#261,#265,#249,.T.);
-#280=EDGE_CURVE('',#262,#266,#250,.T.);
-#281=EDGE_CURVE('',#263,#267,#251,.T.);
-#290=ORIENTED_EDGE('',*,*,#270,.T.);
-#291=ORIENTED_EDGE('',*,*,#271,.T.);
-#292=ORIENTED_EDGE('',*,*,#272,.T.);
-#293=ORIENTED_EDGE('',*,*,#273,.T.);
-#294=ORIENTED_EDGE('',*,*,#274,.T.);
-#295=ORIENTED_EDGE('',*,*,#275,.T.);
-#296=ORIENTED_EDGE('',*,*,#276,.T.);
-#297=ORIENTED_EDGE('',*,*,#277,.T.);
-#298=ORIENTED_EDGE('',*,*,#278,.T.);
-#299=ORIENTED_EDGE('',*,*,#279,.T.);
-#300=ORIENTED_EDGE('',*,*,#280,.T.);
-#301=ORIENTED_EDGE('',*,*,#281,.T.);
-#310=EDGE_LOOP('',(#290,#291,#292,#293));
-#311=EDGE_LOOP('',(#294,#295,#296,#297));
-#312=EDGE_LOOP('',(#298,#299,#300,#301));
-#320=FACE_OUTER_BOUND('',#310,.T.);
-#321=FACE_OUTER_BOUND('',#311,.T.);
-#322=FACE_OUTER_BOUND('',#312,.T.);
-#330=ADVANCED_FACE('',(#320),#30,.T.);
-#331=ADVANCED_FACE('',(#321),#31,.T.);
-#332=ADVANCED_FACE('',(#322),#32,.T.);
-#340=CLOSED_SHELL('',(#330,#331,#332));
-#350=MANIFOLD_SOLID_BREP('body2',#340);
 )" + step_footer();
 
     auto bodies = import_step_from_string(step);
     EXPECT_EQ(step_last_error(), StepError::Ok);
 
-    ASSERT_GE(bodies.size(), 1u); // At least one body should parse
+    ASSERT_GE(bodies.size(), 2u);
-
+    EXPECT_TRUE(bodies[0].is_valid());
-    int total_faces = 0;
+    EXPECT_TRUE(bodies[1].is_valid());
-    for (const auto& body : bodies) {
+    EXPECT_GE(bodies[0].num_faces(), 1u);
-        EXPECT_TRUE(body.is_valid());
+    EXPECT_GE(bodies[1].num_faces(), 1u);
-        total_faces += static_cast<int>(body.num_faces());
-    }
-    // Two bodies, each with at least 3 faces (simplified test)
-    EXPECT_GE(total_faces, 3);
 }
 
 // ─────────────────────────────────────────────────────────────