Voids each orphaned Bill.com bill that SGOS is tracking (failed payments carrying a bill id) and clears the persisted bill id on success, so a payment SGOS reports as failed no longer corresponds to a payable bill in Bill.com (MED-1237 AC3, AC5). Idempotent — safe to re-run; already-voided bills are treated as reconciled.

Restricted to Admin (internal_admin) because it moves financial state in Bill.com.