One of the two is required. --http-upgrade upgrades an HTTP connection to
a WebSocket on /ws, as before, for job-search serve; --url and --origin go
with it. --direct connects straight to ws-test serve over plain TCP, one
JSON message per line, at --addr (default from server.host and
server.port). --ping, --message, --listen and stdin work the same in both
modes. The README's ws-test section explains the two modes.