test: failing regression test for #260: Targeted cut deletes another body that the tool fully covers (#275)

* test: reproduce #260 (Targeted cut deletes another body that the tool fully covers)

* Primitives honour `targets` for join/cut/intersect (#260)

solid.box/cylinder/sphere/torus had no targets field, so a `targets` list was
ignored and every body of the component took part: a targeted cut also cut a
non-target body, and deleted one it covered fully. Their `targets` now become
the feature's participants.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

---------

Co-authored-by: bherbruck <[email protected]>
Co-authored-by: Claude Opus 5.5 <[email protected]>

crates/engine/src/tests.rs

@@ -2511,6 +2511,31 @@ fn special_files_are_refused_by_every_file_command() {
     let _ = std::fs::remove_dir_all(&dir);
 }
 
+/// A cut targeted at one body leaves a non-target body alone, even one the tool covers completely (#260).
+#[test]
+fn targeted_cut_keeps_a_covered_body_that_is_not_a_target() {
+    let mut s = Session::default();
+    run(&mut s, "solid.box", json!({"length": 10, "width": 10, "height": 10, "operation": "new_body", "body_name": "Frame"}));
+    run(&mut s, "solid.box", json!({"length": 10, "width": 10, "height": 10, "corner": [20, 0, 0], "operation": "new_body", "body_name": "Other"}));
+    // Exactly Other's extent; it does not touch Frame.
+    run(&mut s, "solid.box", json!({"length": 10, "width": 10, "height": 10, "corner": [20, 0, 0], "operation": "cut", "targets": ["Frame"]}));
+    let names: Vec<String> = s.model.state().bodies.iter().map(|b| b.name.clone()).collect();
+    assert_eq!(names, ["Frame", "Other"]);
+    assert!(rel(volume(&mut s), 2000.0) < 1e-6);
+}
+
+/// A frame's opening cut over a separate mesh body that sits in it: the mesh survives (#260).
+#[test]
+fn targeted_cut_keeps_an_overlapping_body_that_is_not_a_target() {
+    let mut s = Session::default();
+    run(&mut s, "solid.box", json!({"length": 50, "width": 50, "height": 5, "operation": "new_body", "body_name": "Frame"}));
+    run(&mut s, "solid.box", json!({"length": 30, "width": 30, "height": 1, "corner": [10, 10, 2], "operation": "new_body", "body_name": "Mesh"}));
+    run(&mut s, "solid.box", json!({"length": 30, "width": 30, "height": 5, "corner": [10, 10, 0], "operation": "cut", "targets": ["Frame"]}));
+    let names: Vec<String> = s.model.state().bodies.iter().map(|b| b.name.clone()).collect();
+    assert_eq!(names, ["Frame", "Mesh"]);
+    assert!(rel(volume(&mut s), 50.0 * 50.0 * 5.0 - 30.0 * 30.0 * 5.0 + 900.0) < 1e-6);
+}
+
 /// A join with explicit `targets` merges into those bodies only; a touched non-target stays (#259).
 #[test]
 fn join_with_targets_leaves_other_touched_bodies_alone() {