OnSched 3.9.0 - reschedule controls and booking retention

API

• Silent reschedules: PUT /v3/appointment/{id}/reschedule now accepts skip_notifications: true in the request body. Use it for provider-only or other operational changes that should not send email or SMS to the customer, company, or assigned resources.
• Integrations stay synchronized: Silent reschedules still emit the APPOINTMENT_RESCHEDULED webhook and refresh Google Calendar or Outlook events.
• Backward compatible: Omitting the flag, or setting it to false, keeps existing reschedule notification behavior.

Appointment retention

• Booked records cannot be permanently deleted: DELETE /v3/appointment/{id} rejects BK, CN, and RE appointments. Cancel booked appointments with PUT /v3/appointment/{id}/cancel so billing and lifecycle history remain available.
• Hold cleanup remains available: Initial (IN) and reserved (RS) holds may still be permanently deleted.