FIX: Don't allow editing seeded category security settings

app/serializers/category_serializer.rb

@@ -11,6 +11,7 @@ class CategorySerializer < BasicCategorySerializer
              :suppress_from_homepage,
              :can_delete,
              :cannot_delete_reason,
+             :is_special,
              :allow_badges,
              :custom_fields
 
@@ -37,6 +38,11 @@ class CategorySerializer < BasicCategorySerializer
     true
   end
 
+  def is_special
+    [SiteSetting.lounge_category_id, SiteSetting.meta_category_id, SiteSetting.staff_category_id, SiteSetting.uncategorized_category_id]
+    .include? object.id
+  end
+
   def include_can_delete?
     scope && scope.can_delete?(object)
   end