I have just read your post:
The latest versions of OpenSSH provide tunnelling to local sockets: you can have something like
this in your .ssh/config:
Host myserver
LocalForward 9000 /run/supervisor.sock
or the equivalent command line syntax:
ssh -L 9000:/run/supervisor.sock myserver
I have tried to make use of this with pgAdmin, but unsuccessfully: it insists that the remote end looks like a hostname and a port. It's a shame because authentication on the postgres local socket is completely painless, it just uses my uid, but connecting to the TCP port requires a password and blah blah. Do you know if there are plans to add this very convenient feature to pgAdmin?