Say when the lease is handed away, let the vault and the grants part read it, and let the grants part create the consumers an account needs, so both turn on at the lease write alone (issue 774, ADR 0561 §3, §6)

go/buscompose/derived.go

@@ -247,6 +247,30 @@ func ConsumersOf(users []Principal) []ModuleConsumer {
 	return out
 }
 
+// AccountConsumers are the durable consumers an account needs (novox/hq ADR 0561 §6): of ConsumersOf, each module's on
+// EVENTS and each process's on its own work queue, never one on a module stream it hears (those the controller makes with
+// the stream's grant). The grants part creates them from the lease write, with these configurations.
+func AccountConsumers(users []Principal) []ModuleConsumer {
+	queues := map[string]bool{}
+	for _, p := range users {
+		for _, q := range p.Queues {
+			queues[q.Stream] = true
+		}
+		for _, d := range p.Carries {
+			for _, q := range d.Queues {
+				queues[q.Stream] = true
+			}
+		}
+	}
+	var out []ModuleConsumer
+	for _, mc := range ConsumersOf(users) {
+		if mc.Consumer.Stream == consumerStream(Principal{Kind: KindModule}) || queues[mc.Consumer.Stream] {
+			out = append(out, mc)
+		}
+	}
+	return out
+}
+
 // HolderConsumerFor is the worker a seat's holders share on that seat's work queue.
 //
 // **One worker for every holder, and each holder pulls one ask when it is idle** (novox/hq ADR