Add in-app notifications for moderation actions/warnings (#30065)

app/models/admin/status_batch_action.rb

@@ -65,7 +65,8 @@ class Admin::StatusBatchAction
       statuses.each { |status| Tombstone.find_or_create_by(uri: status.uri, account: status.account, by_moderator: true) } unless target_account.local?
     end
 
-    UserMailer.warning(target_account.user, @warning).deliver_later! if warnable?
+    process_notification!
+
     RemovalWorker.push_bulk(status_ids) { |status_id| [status_id, { 'preserve' => target_account.local?, 'immediate' => !target_account.local? }] }
   end
 
@@ -101,7 +102,7 @@ class Admin::StatusBatchAction
       text: text
     )
 
-    UserMailer.warning(target_account.user, @warning).deliver_later! if warnable?
+    process_notification!
   end
 
   def handle_report!
@@ -127,6 +128,13 @@ class Admin::StatusBatchAction
     !report.nil?
   end
 
+  def process_notification!
+    return unless warnable?
+
+    UserMailer.warning(target_account.user, @warning).deliver_later!
+    LocalNotificationWorker.perform_async(target_account.id, @warning.id, 'AccountWarning', 'moderation_warning')
+  end
+
   def warnable?
     send_email_notification && target_account.local?
   end