Overview

Tenant + tenant-location-scoped destination set for the BACKOFFICE inbound-callback route. Tenants register/reorder/toggle their reception/back-office numbers; active lines ring simultaneously when a customer callback resolves to the BACKOFFICE branch. Loop guard rejects any E.164 already registered as a MaskingPoolNumber. FR-7 single-line+accept rule fires at save time when whisper require_accept=true.