Add ability to email announcements to all users (#33928)

db/migrate/20250221143646_add_notification_sent_at_to_announcements.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddNotificationSentAtToAnnouncements < ActiveRecord::Migration[8.0]
+  def change
+    add_column :announcements, :notification_sent_at, :datetime
+  end
+end