Stream the ANAF e-Factura PDF for an expense imported from the SPV inbox
efactura.pdf_url field from Retrieve Expense
to discover the URL — it is only present when efactura.xml_available is
true.
application/pdf binary content with Content-Disposition: inline.
efactura_not_available)
or its XML file is missing on disk (efactura_xml_missing).efactura_pdf_generation_failed).