Fix service worker handling for updating/deleting

web/src/app/events.js

@@ -7,6 +7,7 @@ export const EVENT_MESSAGE = "message";
 export const EVENT_MESSAGE_DELETE = "message_delete";
 export const EVENT_MESSAGE_CLEAR = "message_clear";
 export const EVENT_POLL_REQUEST = "poll_request";
+export const EVENT_SUBSCRIPTION_EXPIRING = "subscription_expiring";
 
 // Check if an event is a notification event (message, delete, or read)
 export const isNotificationEvent = (event) => event === EVENT_MESSAGE || event === EVENT_MESSAGE_DELETE || event === EVENT_MESSAGE_CLEAR;