for *some reason*, coravel locks a persistent job queue behind a
paywall. this means that if the server ever crashes, all pending jobs
are lost. this is... not good, so we're switching to hangfire for that
instead.
coravel is still used for emails, though.
BREAKING CHANGE: Foxnouns.NET now requires Redis to work. the EFCore
storage for hangfire doesn't work well enough, unfortunately.
change the random base 64 to a directory rather than part of the
filename, so that users downloading their exports aren't greeted with a
completely incomprehensible file in their downloads folder
