Downloads everything the store can read of an invoice, always as an attachment. Named factura-drelife-<YYYY-MM>-<mode>, the mode lowercased (returns, circular, repair) so the invoices of two modes of one month never share a name. With a single document, that document as it is with its own media type and extension (factura-drelife-2026-08-returns.pdf). With several, a ZIP built on the fly (application/zip, factura-drelife-2026-08-returns.zip) holding the invoice document first and then the additional ones; repeated file names get a numeric suffix (sample.pdf, sample (2).pdf). The response must not be cached.