DownloadLog.userAgent

DownloadLog.userAgent captures the User-Agent header of the client that fetched a stored document. It is optional and may be null when the header is absent. Recording it enriches the download audit trail with the kind of client involved — a browser, a server-to-server fetch, or a specific integrating product — which helps when investigating unexpected download patterns. Like the rest of the DownloadLog row, it is written best-effort and never blocks the actual file download.