Add setting for status page URL (#23390)

app/serializers/initial_state_serializer.rb

@@ -33,6 +33,7 @@ class InitialStateSerializer < ActiveModel::Serializer
       single_user_mode: Rails.configuration.x.single_user_mode,
       translation_enabled: TranslationService.configured?,
       trends_as_landing_page: Setting.trends_as_landing_page,
+      status_page_url: Setting.status_page_url,
     }
 
     if object.current_account

app/serializers/rest/instance_serializer.rb

@@ -45,6 +45,7 @@ class REST::InstanceSerializer < ActiveModel::Serializer
     {
       urls: {
         streaming: Rails.configuration.x.streaming_api_base_url,
+        status: object.status_page_url,
       },
 
       accounts: {