Returns one document's details, including who uploaded it and its file information.

file_url is a path relative to the API host that downloads the file. It expires after about 15
minutes, so fetch the document again for a fresh link rather than storing it. file_url and the
other file fields are null when no file is attached.

The token's role must allow viewing all records, or the user must be assigned to the job as its
sales rep or production manager.