Support Github codespaces port forwarding (automatic)

It seems like printing out "localhost:port" will trigger automatic port forwarding. When launching, if we have the server print that out or just have launch echo something out during ssh, it should trigger opening the port for distant.

https://docs.github.com/en/codespaces/developing-in-codespaces/forwarding-ports-in-your-codespace

Start with the launch and SSH output paths mentioned in the issue, then read GitHub's Codespaces port-forwarding documentation. Verify how the server or launch command currently reports localhost ports and define done as producing output that triggers automatic forwarding in Codespaces; no test or file is named in the issue.

Written by the indexing model from the issue text.