There does not appear to be a way for a server to send an exit-status.

I see machinery for sending an SSH protocol "exit-status" `SSHMessage`, and it initializes from `SSHChannelData` (which I can send), but there doesn't seem to be any machinery to encode an "exit-status" in an `SSHChannelData` and get it through into a `SSHMessage.channelRequest`.

That looks to be the right way to send an exit-status, unless I'm missing something obvious.

So, is there a way I'm missing? Or maybe I should make a PR?

Start by tracing the existing SSH protocol "exit-status" SSHMessage initialization and how SSHChannelData reaches SSHMessage.channelRequest. Confirm whether SSHChannelData can represent an exit status; done means a server can encode and transmit the SSH exit-status request through the existing channel path, with coverage for the resulting message.

Written by the indexing model from the issue text.