Reconcile Stuck Number Provisioning Endpoint

Reconcile numbers stuck in provisioning limbo (> 10 min).

Two failure classes this handles:

A. phone_numbers.status = 'pending' from /v1/numbers/purchase where the activation transaction never ran after Telnyx succeeded. B. pending_number_purchases.status = 'ordering' from the BUY_NUMBER webhook path where fulfill crashed after Telnyx order committed.

Strategy: ask Telnyx which numbers it thinks we own. If our 'pending'/'ordering' number is in that list → activate it. If not → it was never ordered or was released; clean up and (for purchase path) refund the user.

Run every 10 minutes via Cloud Scheduler.