[feature request] Integrate mosh for persistent ssh session

[sreeniHari]

@iximiuz Is it possible to integrate mosh to the ssh session ? i am using wezterm and i need to kill the terminal to restart after shell each time after ssh session timeout.

 λ ➜  labctl ssh xxxx
laborant@python-01:~$

[sreeniHari]

last time i had used this in termius.

SSH works over TCP, which means that if the network connection is interrupted, the session may be lost – that's where [Mosh](https://support.termius.com/hc/en-us/articles/4402049882137-Supported-SSH-Capabilities#h_01F7NQXD3ESVM1FYTH0ZYFSZX9) comes in handy

https://support.termius.com/hc/en-us/articles/4402049882137-Supported-SSH-Capabilities

[iximiuz]

Hey @sreeniHari! If I understand correctly, mosh expects the SSH server address to be publicly available. In the labctl case, the playground's SSH server is actually not accessed directly, but instead, a WebSocket (hence, TCP)-powered proxy process is started to punch a tunnel to the playground (see https://github.com/iximiuz/wsmux). Then the SSH connection is established with a local port. Thus, even if you make the connection to this port happen via mosh, restarting a terminal or temporarily losing the Internet connection would break the WebSocket tunnel.