WIP: Save agent roles integration work before CHORUS rebrand

- Agent roles and coordination features
- Chat API integration testing
- New configuration and workspace management

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

vendor/github.com/libp2p/go-libp2p-pubsub/subscription.go

@@ -0,0 +1,51 @@
+package pubsub
+
+import (
+	"context"
+	"sync"
+)
+
+// Subscription handles the details of a particular Topic subscription.
+// There may be many subscriptions for a given Topic.
+type Subscription struct {
+	topic    string
+	ch       chan *Message
+	cancelCh chan<- *Subscription
+	ctx      context.Context
+	err      error
+	once     sync.Once
+}
+
+// Topic returns the topic string associated with the Subscription
+func (sub *Subscription) Topic() string {
+	return sub.topic
+}
+
+// Next returns the next message in our subscription
+func (sub *Subscription) Next(ctx context.Context) (*Message, error) {
+	select {
+	case msg, ok := <-sub.ch:
+		if !ok {
+			return msg, sub.err
+		}
+
+		return msg, nil
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	}
+}
+
+// Cancel closes the subscription. If this is the last active subscription then pubsub will send an unsubscribe
+// announcement to the network.
+func (sub *Subscription) Cancel() {
+	select {
+	case sub.cancelCh <- sub:
+	case <-sub.ctx.Done():
+	}
+}
+
+func (sub *Subscription) close() {
+	sub.once.Do(func() {
+		close(sub.ch)
+	})
+}