> but I didn't see any mechanism for periodically purging expired files or anything like that. (...) should I just set up a cron job or something to delete all files in that directory older than a week?

You're right. Expired files that don't reach their download limit are kept on the server. Due to implementation details there is no 'nice' way to do this from Send itself. If using S3 as storage you can configure a LifeCycle Policy, if using raw disk storage you can set up a cron.

See an example here: https://github.com/timvisee/send-docker-compose/blob/master/...

All uploaded files have a prefixed number which defines the lifetime in days (e.g.: `7-abcdefg` for 7 days expiry). So you can be a little smarter with cleaning up.

I should describe this clearly in documentation.