Can't quit `ceph-salt apply` if it's waiting for node reboots

Ran `ceph-salt apply`, it got to the point of rebooting various nodes, and I realised there was no way to quit, while the UI was still spinning waiting for those rebooted nodes to come back. 'Q' did nothing, CTRL-C did nothing, IIRC I had to CTRL-Z then `kill` it. Should there be a way to quit in this case (or in any case where execution is not yet complete)?


Start by reproducing `ceph-salt apply` while it waits for rebooted nodes, then trace the `ceph-salt apply` command's waiting and interruption behavior. Done means the command provides a reliable way to quit before execution completes, including during node reboot waits; the payload names no files or tests.

Written by the indexing model from the issue text.