Integrate RabbitMQ for background jobs (notifications, payments)

Integrate RabbitMQ for asynchronous background job processing.

Requirements:

• Setup RabbitMQ message broker
• Create message queues for notifications, payments, and emails
• Implement job producers (API endpoints that trigger jobs)
• Implement job consumers/workers
• Add retry logic and dead letter queue handling
• Setup monitoring for queue health

Deliverables:

• RabbitMQ configuration
• Message producer service
• Worker/consumer implementations
• Job definitions for notifications, payments, and emails
• Error handling and retry policies