Add real-time developer messaging via NATS

- Add SendMessageTool for sending messages to other devs
- Add ReceiveMessagesTool for receiving messages
- Auto-detect sender role from workspace path (admin-dev/api-dev/web-dev)
- Messages published to NATS channels: dev.messages.{role}
- Enable real-time communication between Claude instances

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

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

src/registry/ToolRegistry.ts

@@ -8,9 +8,10 @@ const logger = createLogger('ToolRegistry');
 
 export class ToolRegistry {
   private tools = new Map<string, ToolDefinition>();
-  private builtinHandlers = createBuiltinTools();
+  private builtinHandlers: Map<string, ToolHandler>;
 
   constructor(private natsClient: NatsClient) {
+    this.builtinHandlers = createBuiltinTools(natsClient);
     this.registerBuiltinTools();
   }