Schema tests: an empty face list is checked on the draft, which refuses it

solid.shell takes faces: [] since 1df330c79 (a closed hollow body), so its row in
shared_types_keep_the_handlers_messages no longer matched the shared FaceRefs message. The row
uses solid.draft, which still refuses it; FaceRefs says shell's exception.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/engine/src/schema/tests.rs

@@ -699,7 +699,8 @@ fn shared_types_keep_the_handlers_messages() {
     for (id, p, probe) in [
         ("solid.shell", json!({"thickness": 1, "faces": 5}), json!({"faces": 5})),
         ("solid.shell", json!({"thickness": 1, "faces": null}), json!({"faces": null})),
-        ("solid.shell", json!({"thickness": 1, "faces": []}), json!({"faces": []})),
+        // `solid.shell` takes no faces (a closed hollow body); the draft refuses them.
+        ("solid.draft", json!({"angle": 1, "faces": []}), json!({"faces": []})),
         ("solid.shell", json!({"thickness": 1, "faces": [true]}), json!({"faces": [true]})),
         ("solid.shell", json!({"thickness": 1, "faces": [""]}), json!({"faces": [""]})),
         ("solid.fillet", json!({"radius": 1, "edges": {}}), json!({"edges": {}})),

crates/engine/src/schema/types.rs

@@ -730,8 +730,8 @@ macro_rules! pick_list {
 
 pick_list!(
     /// The `faces` of `solid.shell`, `solid.draft`, `solid.offset_face`, `solid.split_face` and
-    /// `face.delete`, as `features::face_points` reads them. (Extrude's `faces` is a
-    /// [`FacesParam`].)
+    /// `face.delete`, as `features::face_points` reads them; `solid.shell` also takes an empty
+    /// list (a closed hollow body). (Extrude's `faces` is a [`FacesParam`].)
     FaceRefs,
     FaceRef,
     "`faces` must be a list of points or face names",