FluentCart downloads and storage

Separate file metadata, commercial entitlement, signed delivery, and download accounting. Possession of a path, download ID, or signed URL must not create a new entitlement.

Read download-delivery.md before generating links, changing access rules, or implementing a driver.

Preserve the delivery chain

Use ProductDownload records to map product/variation availability to driver metadata. Use Order::getDownloads() or the customer-profile flow to obtain entitled files. Generate delivery links with Helper::generateDownloadFileLink($download, $orderId).