R-11: mesh/publish with ack answers its sequence or {error}, mesh/subscribe with deliver new makes an ordered consumer; finding-calls is stated

The subscription's key resolves through mesh-sdk's buscompose.EventSubjects (lead answer A-153; the sdk commit EE-S1 is
cherry-picked into this change's sdk placement), a wildcard is refused.

Builds: design 47 G §559, §488, §576, §622

Claude-Session: https://claude.ai/code/session_01NcbgfGKaxw984XyAPfLm4h

node-tools/internal/bus/bus.go

@@ -852,6 +852,12 @@ func answerOf(data []byte) (Answered, error) {
 // PublishAs emits an event as a module: published into JetStream and awaited, de-duplicated by its
 // own id (ADR 0042). The body is the payload; the metadata rides as headers.
 func (c *Conn) PublishAs(module string, env Envelope) error {
+	_, err := c.PublishAsAcked(module, env)
+	return err
+}
+
+// PublishAsAcked is PublishAs that also answers the sequence the bus acknowledged the event at.
+func (c *Conn) PublishAsAcked(module string, env Envelope) (uint64, error) {
 	// On the module's own stream when its membership names one carrying the event (ADR 0363 §2), on EVENTS
 	// otherwise — and only there, as before, for a membership that names no stream.
 	msg := nats.NewMsg(eventSubject(c.Membership(module), module, env.Key))
@@ -873,8 +879,11 @@ func (c *Conn) PublishAs(module string, env Envelope) error {
 	if id := env.Headers["x-event-id"]; id != "" {
 		opts = append(opts, nats.MsgId(id))
 	}
-	_, err := c.js.PublishMsg(msg, opts...)
-	return err
+	ack, err := c.js.PublishMsg(msg, opts...)
+	if err != nil {
+		return 0, err
+	}
+	return ack.Sequence, nil
 }
 
 // Say publishes one message on core NATS, kept by nobody: a heartbeat, whose loss is the next one.

node-tools/internal/bus/subscribenew.go

@@ -0,0 +1,87 @@
+package bus
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"slices"
+	"strings"
+
+	"git.novox.be/novox/mesh-sdk/go/buscompose"
+	"github.com/nats-io/nats.go/jetstream"
+)
+
+// SubscribeNew hears one event, named `<emitter>.<event>`, from the next message on, on an ordered consumer of its own on each
+// stream that carries it, and hands every message to deliver as the envelope a module sees. The subjects the name lands on are
+// mesh-sdk's one rule (buscompose.EventSubjects, design 47 G §559, A-153), so a name with a wildcard is refused, naming the rule;
+// a name no stream on the bus carries is an error, never a subscription that hears nothing. stop ends every consumer.
+func (c *Conn) SubscribeNew(name string, deliver func(json.RawMessage) error) (func(), error) {
+	subjects, err := buscompose.EventSubjects(name, "")
+	if err != nil {
+		return nil, err
+	}
+	js, err := c.JetStream()
+	if err != nil {
+		return nil, err
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), StateTimeout)
+	defer cancel()
+	// The streams that carry each subject, found by the bus: a namespace no stream carries hears nothing and is skipped.
+	byStream := map[string][]string{}
+	for _, subject := range subjects {
+		if strings.HasSuffix(subject, ".>") {
+			continue
+		}
+		stream, err := js.StreamNameBySubject(ctx, subject)
+		if err != nil || stream == "" {
+			continue
+		}
+		byStream[stream] = append(byStream[stream], subject, subject+".>")
+	}
+	if len(byStream) == 0 {
+		return nil, fmt.Errorf("no stream on the bus carries %s (%s): nothing would be heard", name, strings.Join(subjects, ", "))
+	}
+	var stops []func()
+	stopAll := func() {
+		for _, s := range stops {
+			s()
+		}
+	}
+	for _, stream := range slices.Sorted(mapKeys(byStream)) {
+		cons, err := js.OrderedConsumer(ctx, stream, jetstream.OrderedConsumerConfig{FilterSubjects: byStream[stream],
+			DeliverPolicy: jetstream.DeliverNewPolicy})
+		if err != nil {
+			stopAll()
+			return nil, fmt.Errorf("an ordered consumer of %s on %s: %w", name, stream, err)
+		}
+		cc, err := cons.Consume(func(m jetstream.Msg) {
+			env, ok := envelopeOf(m.Subject(), m.Headers(), m.Data())
+			if !ok {
+				return
+			}
+			raw, err := json.Marshal(env)
+			if err != nil {
+				return
+			}
+			if err := deliver(raw); err != nil && c.Logf != nil {
+				c.Logf("[mesh-tools] a subscription for new %s messages did not take one: %v", name, err)
+			}
+		})
+		if err != nil {
+			stopAll()
+			return nil, fmt.Errorf("consuming %s on %s: %w", name, stream, err)
+		}
+		stops = append(stops, cc.Stop)
+	}
+	return stopAll, nil
+}
+
+func mapKeys(m map[string][]string) func(func(string) bool) {
+	return func(yield func(string) bool) {
+		for k := range m {
+			if !yield(k) {
+				return
+			}
+		}
+	}
+}