Fix artificial Shell wall splits on stepped bodies

crates/kernel/src/meshbody.rs

@@ -109,6 +109,7 @@ pub fn mesh_body(positions: &[Vec3], triangles: &[[u32; 3]]) -> Result<Body> {
         paint: None,
         splits: None,
         face_sources: None,
+        regularization_protected: false,
     })
 }
 
@@ -201,6 +202,7 @@ impl Body {
             paint: self.paint.clone(),
             splits: self.splits.clone(),
             face_sources: None,
+            regularization_protected: self.regularization_protected,
         })
     }
 }