[Conversations API v2] Desktop channel conversations not sending notifications for Fibi responses before handover

Conversations API v2 with desktop channel is not sending notifications for Fibi AI responses.

Specifically, notifications are not being sent to the customer/user when Fibi replies, and it seems this only starts working once a human handover is triggered.

This is causing 'silent failures' where the AI thinks it has answered the customer, but the customer never receives the email/notification.