Get phone number

Retrieve the current status of a purchased phone number. Poll this to track Meta pre-verification (US sync path) and, for regulated (Tier 3/4) numbers, the async lifecycle: pending_regulatory → active (or regulatory_declined). When a regulated number has an Onfido ID step, onfidoVerificationUrl appears here once the order is placed — forward it to the end user. (Or subscribe to the whatsapp.number.* webhooks instead of polling.)