Cargo: codec e023bc3 (acadrust sync), kernel abca4e8, graph c63556f

The codec now holds wide EntityType variants boxed (MText, Helix,
Dimension, Hatch, Viewport, MultiLeader, Surface, Table, Ole2Frame,
Light, Extended). Constructors box their entity; nested patterns reach
a dimension through entities::dimension::as_dimension(_mut). Also
follows BlockAction::action_ids, LineTypeComplexData::source_flags and
the decimal tab stop with an explicit character.

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

tests/annotative_context_synthesis.rs

@@ -20,7 +20,7 @@ fn empty_annotation_scales_is_not_annotative() {
     let mut doc = CadDocument::with_version(DxfVersion::AC1032);
     let mut m = MText::new();
     m.is_annotative = false; // no native flag, no annotative style
-    let ent = doc.add_entity(EntityType::MText(m)).unwrap();
+    let ent = doc.add_entity(EntityType::MText(Box::new(m))).unwrap();
 
     // Build xdict -> "AcDbContextDataManager" -> "ACDB_ANNOTATIONSCALES" (empty).
     let mk = |doc: &mut CadDocument, owner: Handle| -> Handle {
@@ -92,7 +92,7 @@ fn ocs_synthesized_mtext_context_survives_dwg_roundtrip() {
     m.insertion_point = Vector3::new(100.0, 200.0, 0.0);
     m.rectangle_width = 50.0;
     m.is_annotative = true;
-    let ent = doc.add_entity(EntityType::MText(m)).expect("add mtext");
+    let ent = doc.add_entity(EntityType::MText(Box::new(m))).expect("add mtext");
 
     let sh = doc.allocate_handle();
     let mut scale = Scale::new("1:50", 1.0, 50.0);
@@ -174,7 +174,7 @@ fn object_scale_membership_add_remove_roundtrips() {
     let mut doc = CadDocument::with_version(DxfVersion::AC1032);
     let mut m = MText::new();
     m.insertion_point = Vector3::new(1.0, 2.0, 0.0);
-    let ent = doc.add_entity(EntityType::MText(m)).unwrap();
+    let ent = doc.add_entity(EntityType::MText(Box::new(m))).unwrap();
 
     let mk_scale = |doc: &mut CadDocument, name: &str, d: f64| {
         let h = doc.allocate_handle();