Add automatic notifications for incoming messages

- ReceiveMessagesTool now logs notifications when messages arrive
- Console output shows: from, subject, and message preview
- Automatic real-time alerts via NATS subscription
- Enables passive message monitoring without polling

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

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

src/tools/builtin/messaging.ts

@@ -75,7 +75,7 @@ export class ReceiveMessagesTool extends ToolHandler<ReceiveMessagesInput, any>
   private messages: any[] = [];
   private subscribed = false;
 
-  constructor(private natsClient: NatsClient) {
+  constructor(private natsClient: NatsClient, private server?: any) {
     super(
       {
         name: 'receive_messages',
@@ -95,6 +95,9 @@ export class ReceiveMessagesTool extends ToolHandler<ReceiveMessagesInput, any>
     try {
       this.natsClient.subscribe(channel, (msg) => {
         this.messages.push(msg);
+
+        // Send notification to Claude Code UI
+        this.notifyNewMessage(msg);
       });
       this.subscribed = true;
     } catch (error) {
@@ -102,6 +105,11 @@ export class ReceiveMessagesTool extends ToolHandler<ReceiveMessagesInput, any>
     }
   }
 
+  private notifyNewMessage(msg: any) {
+    const preview = msg.message?.substring(0, 100) || '';
+    console.log(`\n📬 NEW MESSAGE from ${msg.from}\n   Subject: ${msg.subject}\n   Preview: ${preview}...\n`);
+  }
+
   protected async handle(input: ReceiveMessagesInput, _context: ToolContext): Promise<any> {
     // Setup subscription on first use (after NATS is connected)
     this.setupSubscription();