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.

cmd/mesh-controller/push.go

@@ -182,6 +182,9 @@ func serve(ctx context.Context) (err error) {
 	if err := server.Watches(standings{keeper: func() *conditions.Keeper { return conditionsFrom }}); err != nil {
 		return err
 	}
+	// And what each machine says of what it runs between its reports, kept and raised from (novox/hq ADR
+	// 0240): the gate, `node show` and the conditions read it.
+	server.Hears(moduleHealth{inv: inv, keeper: func() *conditions.Keeper { return conditionsFrom }})
 	// And what they say about consumers the mesh stopped asking for: one waiting for a person is an
 	// urgent condition, and an act asked of a provider some other way is recorded by hand (ADR 0230).
 	if err := server.KeepsRetirements(retirements{keeper: func() *conditions.Keeper { return conditionsFrom },