fix(properties): name AEC / proxy objects instead of "Unknown"

Selecting a proxy object we render from its cached graphics (an AEC
Wall/Door/Window and the like) showed "Unknown" as its type. The entity
now carries its real DXF class name from the CLASSES section (acadrust
bump), so surface it: ui_name_or_class title-cases the class ("AEC_WALL"
→ "Aec Wall") for the properties Type row and the status-bar label, and
still says "Unknown" only when the class truly can't be named.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/scene/cache/properties.rs

@@ -140,7 +140,7 @@ pub fn fallback_properties(_handle: Handle, entity: &EntityType) -> PropSection
         props: vec![Property {
             label: "Type".into(),
             field: "type",
-            value: PropValue::ReadOnly(crate::entities::names::ui_name(entity).into()),
+            value: PropValue::ReadOnly(crate::entities::names::ui_name_or_class(entity).into()),
         }],
     }
 }