fix(blocks): a copied dynamic reference changes state on its own (#1818)

COPY cloned the reference's AcDbRepData without its handle, owner or
representation index, and both references kept sharing one evaluated *U
block, so a state picked on either changed both. The clone now names
itself and is indexed; a state change gives a reference whose *U other
references share its own copy first.

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

src/app/visibility.rs

@@ -186,19 +186,11 @@ impl OpenCADStudio {
             return;
         }
 
-        // A reference to the definition itself gets an evaluated copy first,
-        // so the state picked for it leaves the definition alone.
-        let direct = {
-            let doc = &self.tabs[i].scene.document;
-            matches!(doc.get_entity(insert_handle), Some(EntityType::Insert(ins))
-            if doc.block_records.get(&ins.block_name).is_some_and(|record| {
-                crate::scene::block_visibility::parameter(doc, record.handle).is_some()
-            }))
-        };
-        if direct {
-            self.push_undo_snapshot(i, "Visibility State");
-            self.tabs[i].scene.visibility_representation(insert_handle);
-        }
+        // A reference to the definition itself, or to a copy other
+        // references share, gets its own evaluated copy first, so the state
+        // picked for it leaves the definition and the others alone.
+        self.push_undo_snapshot(i, "Visibility State");
+        self.tabs[i].scene.visibility_representation(insert_handle);
 
         // Resolve everything against an immutable borrow first.
         let mapping = {
@@ -216,10 +208,6 @@ impl OpenCADStudio {
             return;
         };
 
-        if !direct {
-            self.push_undo_snapshot(i, "Visibility State");
-        }
-
         // Apply invisibility flags to the anonymous block's members.
         {
             let doc = &mut self.tabs[i].scene.document;