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/app/helpers.rs

@@ -333,7 +333,7 @@ pub(super) fn next_group_auto_name(scene: &crate::scene::Scene) -> String {
 // ── Entity type labels ─────────────────────────────────────────────────────
 
 pub(super) fn entity_type_label(entity: &acadrust::EntityType) -> String {
-    crate::entities::names::ui_name(entity).to_string()
+    crate::entities::names::ui_name_or_class(entity)
 }
 
 pub(super) fn entity_type_key(entity: &acadrust::EntityType) -> String {