Six cases. The load-bearing one is the first: every deploy in the tree
writes a bare path, and it must keep meaning a unix socket with no
handshake in front of the payload.
The rest cover the tcp seam: a good token round-trips, a wrong one comes
back ErrUnauthorized, a stranger that speaks HTTP at the port is dropped
while the listener stays up for the next peer, and a tokenless tcp bind
fails rather than serving his turns to anyone who connects.
