Pay-UI Refunds – 500 when fetching service-account-created invoices

Fetching an invoice created by a service account (e.g. NR service account, invoice 11338052) on the MVP Refunds page returns 500.

Root cause: Service-account invoices store the client name (ACCOUNT-NAME-...) as account id instead of a numeric org id. check_auth() calls auth-api orgs/{name}/authorizations → 404 → pay-api returns 500.

Workaround (verified): Submit refund directly via Postman — POST /api/v1/payment-requests/{invoice_id}/refunds with staff token and body {"reason": "..."} → 202. The POST path skips the org lookup.

Fix: In pay-api check_auth(), when caller is staff and account id is non-numeric (service account), skip the org authorization call and use the staff branch instead of surfacing 404 as 500.

Start in pay-api's check_auth() and trace the invoice-fetch request for service-account invoice 11338052. Verify the MVP Refunds page no longer returns 500 for a non-numeric service-account id, while the staff refund endpoint POST /api/v1/payment-requests/{invoice_id}/refunds still returns 202.

Written by the indexing model from the issue text.