nREPL client via UNIX domain sockets

[onetom]

Problem

nREPL supports communication over UNIX domain socket files instead of TCP ports:

$ mkdir -m go-rwx nrepl-test
$ clj -M:nREPL -m nrepl.cmdline --socket nrepl-test/socket &
$ clj -M:nREPL -m nrepl.cmdline --socket nrepl-test/socket --connect

Docs: https://nrepl.org/nrepl/usage/server.html#starting-a-server

Cursive doesn't support specifying a UNIX domain socket file in its "Remote" Clojure REPL run configs.

It's also a misnomer, if we put such an option under the "Remote" config, because it's very much local, out of the box, at least.

Motivation

It could simplify AI agent interactions with nREPLs, since they can discover UNIX domain socket files with their built-in file-finding tools.

Related Slack conversation:
https://clojurians.slack.com/archives/C0744GXCJ/p1774404045963239?thread_ts=1773828992.524469&cid=C0744GXCJ