feat(styles): overhaul style managers

Unify editor layouts, live previews, comparisons, read-only behavior, and localized controls across all named style managers.

Refs #629

src/app/style_ops.rs

@@ -301,7 +301,7 @@ impl OpenCADStudio {
         }
     }
 
-    fn style_in_use(&self, kind: StyleKind, name: &str) -> bool {
+    pub(super) fn style_in_use(&self, kind: StyleKind, name: &str) -> bool {
         use acadrust::entities::EntityType;
 
         let i = self.active_tab;
@@ -613,6 +613,20 @@ impl OpenCADStudio {
 
     pub(super) fn style_delete(&mut self, kind: StyleKind) {
         let name = self.style_selected(kind);
+        if matches!(kind, StyleKind::Dim)
+            && self.tabs[self.active_tab]
+                .scene
+                .document
+                .dim_styles
+                .get(&name)
+                .is_some_and(|style| {
+                    style.xref_reference || style.xref_dependent || !style.xref_handle.is_null()
+                })
+        {
+            self.command_line
+                .push_error(crate::t!("Referenced styles are read only.").as_ref());
+            return;
+        }
         if name.eq_ignore_ascii_case("Standard") {
             self.command_line
                 .push_error(crate::t!("Cannot delete the Standard style.").as_ref());
@@ -657,6 +671,20 @@ impl OpenCADStudio {
         if new.is_empty() || new.eq_ignore_ascii_case(&old) {
             return;
         }
+        if matches!(kind, StyleKind::Dim)
+            && self.tabs[self.active_tab]
+                .scene
+                .document
+                .dim_styles
+                .get(&old)
+                .is_some_and(|style| {
+                    style.xref_reference || style.xref_dependent || !style.xref_handle.is_null()
+                })
+        {
+            self.command_line
+                .push_error(crate::t!("Referenced styles are read only.").as_ref());
+            return;
+        }
         if old.eq_ignore_ascii_case("Standard") {
             self.command_line
                 .push_error(crate::t!("Cannot rename the Standard style.").as_ref());