Add workshop registrants to central attendee tracking sheet

You get registration webhooks without a central attendee record, causing prep gaps and duplicate outreach. Keep the attendee sheet current so coordinators finish prep before each session.

Overview

When registrations arrive as raw webhooks, your coordinators often miss adding them to the roster, which leads to last-minute scramble before sessions. This flow captures each signup into your master sheet and flags duplicates so coordinators have an accurate attendee list within minutes.