Accept/Decline and Invitation Icons Missing for Invited User in Recurring Meetings

Summary

Invited users don't see Accept/Decline buttons or the pending-invite icon for recurring meetings, while single meetings work correctly. The backend correctly returns recurring occurrences with invite_status: "pending" and type: "instance", but the frontend's isPendingEvent() was gated by isEvent(), which excludes type: "instance". As a result, pending recurring instances never render the invite UI