Fix: Defer NATS subscription until after connection

- Remove setupSubscription() call from constructor
- Call setupSubscription() on first handle() invocation
- Prevents 'NATS not connected' error during initialization
- Subscription happens after NATS client is connected

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

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

src/tools/builtin/messaging.ts

@@ -65,6 +65,7 @@ export class SendMessageTool extends ToolHandler<SendMessageInput, any> {
 
 export class ReceiveMessagesTool extends ToolHandler<ReceiveMessagesInput, any> {
   private messages: any[] = [];
+  private subscribed = false;
 
   constructor(private natsClient: NatsClient) {
     super(
@@ -74,20 +75,29 @@ export class ReceiveMessagesTool extends ToolHandler<ReceiveMessagesInput, any>
       },
       ReceiveMessagesSchema,
     );
-    this.setupSubscription();
   }
 
   private setupSubscription() {
+    if (this.subscribed) return;
+
     const myRole = detectRole();
     const channel = `dev.messages.${myRole}`;
 
-    // Subscribe to messages for this role
-    this.natsClient.subscribe(channel, (msg) => {
-      this.messages.push(msg);
-    });
+    // Subscribe to messages for this role (only if NATS is connected)
+    try {
+      this.natsClient.subscribe(channel, (msg) => {
+        this.messages.push(msg);
+      });
+      this.subscribed = true;
+    } catch (error) {
+      // NATS not connected yet, will be called later
+    }
   }
 
   protected async handle(input: ReceiveMessagesInput, _context: ToolContext): Promise<any> {
+    // Setup subscription on first use (after NATS is connected)
+    this.setupSubscription();
+
     const limit = input.limit || 10;
     const recentMessages = this.messages.slice(-limit);