Download a document attached to a business formation order — typically the filed articles, certificate of formation, or other state-issued PDFs as the order progresses.

Returns raw binary data (PDF, ZIP, or image depending on document type), not a JSON envelope. Programmatic clients should treat the response body as bytes and write to disk; browser-side fetch/axios consumers must explicitly handle the binary stream (e.g., responseType: 'blob').

Documents are typically not available immediately after POST /create-order — they populate as the order advances through state-filing phases. A 404 or empty response shortly after order creation usually means the document hasn't been generated yet, not that the order is missing.