A machine that wakes or moves says so, instead of waiting to be told

A suspended laptop's connection is dead the moment it wakes, and the socket
looks perfectly healthy from inside the process — no error, no close, because
nothing has tried to send anything. Heartbeats find out twenty or thirty
seconds later. For that time the node believes it is in a mesh it has left,
which is the one state this design says must never be indistinguishable from
being connected. The machine knew immediately.

So being roused ends the current attempt rather than only shortening the wait
after it: shortening the wait would do nothing at all, because the process is
not waiting — it is sitting inside a connection that will not return.

A signal, because nothing may listen on a node (novox/hq ADR 0004). A socket
for this would be a control surface on every machine, reachable by anything
that can reach the machine, in exchange for saving twenty seconds — and the
whole security argument rests on there not being one.

Two rouses in the same instant are one: a machine suspending and resuming
repeatedly must not build a backlog of reconnections to work through. And the
backoff is not reset by being roused — that says the machine changed, not that
whatever was refusing the connection has stopped, and a laptop woken on a
network with no route would otherwise retry at full speed for as long as
somebody keeps opening the lid.

The dispatcher acts on the events that change where packets go and not on
`down`: the link is already gone there, reconnecting will fail, and the backoff
exists for exactly that.

Makefile

@@ -23,6 +23,7 @@ hosts:
 packaging-test:
 	@./packaging/rollback_test.sh
 	@./packaging/launch_test.sh
+	@./packaging/roused_test.sh
 
 fmt:
 	@test -z "$$(gofmt -l . )" || { echo "unformatted:"; gofmt -l . ; exit 1; }