Route instructor cancellations to regional ops channels now

Instructor cancellation form responses arrive untriaged, leaving sessions unstaffed. It routes each request to the correct regional channel and logs an audit row so teams can respond same day.

Overview

When an instructor cancels, regional coordinators need immediate context to reassign or reschedule. This flow drops a formatted cancellation message into the right regional ops channel and logs an audit row so coordinators can act and confirm changes same day.