Persistent naming: shell inner faces named after the wall face they offset (F<shell>:inner:<face>), sweep and loft faces by start/end caps and the profile curve each side sweeps

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01AS5Tn3xieewUSg3uxrMVdL

crates/engine/src/tests.rs

@@ -1355,6 +1355,17 @@ mod naming {
         assert_eq!(sk.map(|z| (z * 1e6).round() / 1e6), Some(10.0));
     }
 
+    #[test]
+    fn shell_inner_faces_are_named_after_the_walls() {
+        let mut s = Session::default();
+        run(&mut s, "PrimitiveBox", json!({"length": 40, "width": 30, "height": 20, "body_name": "B"}));
+        run(&mut s, "FusionShellBodyCommand", json!({"faces": [[20, 15, 20]], "thickness": 2}));
+        let n = face_names(&mut s, "B");
+        for want in ["F2:inner:F1:-z", "F2:inner:F1:+x", "F2:inner:F1:-x", "F2:inner:F1:+y", "F2:inner:F1:-y"] {
+            assert!(n.contains(&want.to_string()), "{want} in {n:?}");
+        }
+    }
+
     #[test]
     fn shell_and_hole_faces_follow_by_name() {
         let mut s = Session::default();