Serve a module's log verbs so its record outlives a bucket's cap and the events' week (ADR 0297, issues 501, 502)

The runtime answers mesh/log.append, read, last and info for a log issued
in the module's membership, by publish, batch direct get and stream info
alone. A stale expect is refused as a lost state update, so a module tells
it by the same code.

node-tools/internal/meshtest/meshtest.go

@@ -231,3 +231,32 @@ func (m *Mesh) Bucket(t *testing.T, name string) nats.KeyValue {
 	}
 	return kv
 }
+
+// Log makes a module's log afresh as the controller does from the catalogue (novox/hq ADR 0297): a file
+// stream named LOG_<module>_<name> on mesh.log.<module>.<name>.>, limits retention, no age, no cap per
+// key, the declared cap, 256 KiB an entry, refusing new entries when full, direct get, no delete or
+// purge. It answers the membership entry the controller issues for it.
+func (m *Mesh) Log(t *testing.T, module, name string, maxBytes int64) bus.LogIssued {
+	t.Helper()
+	stream := "LOG_" + module + "_" + name
+	subject := "mesh.log." + module + "." + name
+	_ = m.js.DeleteStream(stream)
+	if _, err := m.js.AddStream(&nats.StreamConfig{Name: stream, Subjects: []string{subject + ".>"},
+		Storage: nats.FileStorage, Retention: nats.LimitsPolicy, MaxAge: 0, MaxMsgsPerSubject: -1,
+		MaxBytes: maxBytes, MaxMsgSize: 256 * 1024, Discard: nats.DiscardNew, AllowDirect: true,
+		DenyDelete: true, DenyPurge: true, Replicas: 1,
+		Description: module + "'s log " + name + ", kept as its record (novox/hq ADR 0297)"}); err != nil {
+		t.Fatal(err)
+	}
+	return bus.LogIssued{Name: name, Stream: stream, Subject: subject, Writes: true}
+}
+
+// Consumers is how many consumers a stream has.
+func (m *Mesh) Consumers(t *testing.T, stream string) int {
+	t.Helper()
+	info, err := m.js.StreamInfo(stream)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return info.State.Consumers
+}