cmdbridge does not clean up after itself

Currently cmdbridge processes stay around on remote linux devices and require manual interaction to remove them.

It would be good to have a mechanism to by which a cmdbridge process can clean up by itself (i.e. remove binary, kill process), e.g. after some period of time without communication with the host.

The timeout should be rather large (1 day? 1 week?) to not interfere with regular uses which may involved lengthy periods of inactivity, ideally it could be configured when the cmdbridge is started, or even at runtime.

Independently, there might be mechanisms to notice a dropped connection.