fix(blocks): a dynamic block copied to another drawing stays dynamic (#1816)

Only the definition's entities crossed drawings: its record's object
graph (parameters, visibility states, grips) stayed behind, and a
reference showing an evaluated copy lost the link to its definition.
The clipboard now captures the graph and the dynamic definition of an
evaluated reference, and paste and the block palette's insert-from-file
recreate them on the new records, re-pointing members and element tags.

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

src/scene/block_authoring.rs

@@ -348,7 +348,7 @@ pub(super) fn dynamic(
     object
 }
 
-pub(super) fn members(document: &CadDocument, definition: Handle) -> Vec<Handle> {
+pub(crate) fn members(document: &CadDocument, definition: Handle) -> Vec<Handle> {
     document
         .block_records
         .iter()
@@ -409,6 +409,16 @@ pub(super) fn set_entity_tag(
     }
 }
 
+/// Point each tagged member's element tag back at the member itself, after
+/// the definition was copied onto new handles.
+pub(crate) fn retag_members(document: &mut CadDocument, definition: Handle) {
+    for handle in members(document, definition) {
+        if let Some(id) = document.get_entity(handle).and_then(element_id) {
+            set_entity_tag(document, handle, element_tag(id, handle));
+        }
+    }
+}
+
 /// Give every object of the definition its element tag, numbering the new
 /// ones after the highest id in use, and record the next id on the block.
 pub(super) fn tag_members(document: &mut CadDocument, definition: Handle) {

src/scene/block_visibility.rs

@@ -521,11 +521,7 @@ impl Scene {
         record.flags.anonymous = true;
         let copy = record.handle;
         // The copies keep their element ids, now naming themselves.
-        for handle in members(&self.document, copy) {
-            if let Some(id) = self.document.get_entity(handle).and_then(element_id) {
-                set_entity_tag(&mut self.document, handle, element_tag(id, handle));
-            }
-        }
+        super::block_authoring::retag_members(&mut self.document, copy);
         let mut tag = ExtendedDataRecord::new(REPRESENTATION_TAG);
         tag.add_value(XDataValue::Integer16(1));
         tag.add_value(XDataValue::Handle(definition));