Downloads several invoices at once as a ZIP built on the fly (application/zip, Facturas Drelife.zip), always, even for a single id: everything under a Facturas Drelife/ folder, holding one folder per invoice named by its month (Facturas Drelife/2026-08/, Facturas Drelife/2026-08 (2)/ when two share it) and, when the selection spans several modes, by its mode as well (Facturas Drelife/2026-08 Returns/, Facturas Drelife/2026-08 Repair/), in the order of ids, each holding its documents as GET /invoices/{id}/download does (invoice document first, repeated file names suffixed). An invoice without documents gets no folder. Every id must be an invoice of the marketplace the store can see, and every document must be available, before anything is streamed. The response must not be cached. Declared before GET /invoices/{id}/download for readability only: the methods differ.