feat: add OLE2Frame interactivity + fix Shape rotation from DXF

OLE2Frame: full TruckConvertible/Grippable/PropertyEditable/Transformable
impls in src/entities/ole2frame.rs — grips on corners + center, properties
panel, translate/scale transforms.

Shape: rotation (DXF code 50) now converted degrees→radians on load in
fix_dxf_dimension_rotations(), matching Dimension and Attribute behaviour.

All ❌ gaps resolved. Remaining: Viewport GPU scissor, LWPolyline plinegen.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/io/mod.rs

@@ -221,6 +221,9 @@ fn fix_dxf_dimension_rotations(doc: &mut CadDocument) {
             EntityType::AttributeEntity(a) => {
                 a.rotation = a.rotation.to_radians();
             }
+            EntityType::Shape(s) => {
+                s.rotation = s.rotation.to_radians();
+            }
             _ => {}
         }
     }