Expand Zapier integration: more triggers, actions and payload fields

Expand the existing Zapier integration with new actions and triggers, and richer payloads. Specific asks: actions to create a client under an existing organization, move a client to an organization, and update request following; an 'Organization Created' trigger; a 'Pause Subscription' trigger; enhanced payment-notification payload; sending the client's plan selection in the client-created trigger; and additional fields across existing Zaps.