Keep what each machine says of what it runs, raise it, and gate on it (hq ADR 0240, to-be 48 Phase A)

The gate judged a module by what the mesh saw from outside, so a container that
crash-looped after it applied passed it. Each machine's node-engine now states
the health of every long-running resource it runs; the controller keeps the
newest statement per machine, raises module.<module>.<machine>.unhealthy on the
second statement in a row, clears it on the first that does not say it, and the
gate passes a module only when every long-running resource of it is stated
healthy since the send. An engine that states nothing is judged as before.

internal/link/protocol_test.go

@@ -25,6 +25,13 @@ func TestTheWireFormatIsExactlyTheseFieldNames(t *testing.T) {
 			[]string{"protocol", "address", "port", "by", "published", "container-port"}},
 		{EnrolRequest{Node: "n", Secret: "s", PublicKey: []byte("k")},
 			[]string{"node", "secret", "public_key"}},
+		// novox/hq ADR 0240: every long-running resource's health, in every report and in its own event.
+		{Report{Node: "n", Health: &Health{Contract: LivenessContract}}, []string{"node", "health"}},
+		{Health{Contract: LivenessContract, Resources: []ResourceHealth{}}, []string{"contract", "at", "resources"}},
+		{ResourceHealth{Module: "m", Resource: "m.r", Kind: "container", Target: "t", State: StateUnhealthy,
+			Reason: "restarting", Streak: 2, Restarts: 3},
+			[]string{"module", "resource", "kind", "target", "state", "reason", "since", "streak", "restarts"}},
+		{HealthSaid{Node: "n"}, []string{"node", "health"}},
 	} {
 		raw, err := json.Marshal(c.value)
 		if err != nil {