[BE-08] Implement BullMQ job queue for async operations - installed but never configured

[Leothosine]

Problem

@nestjs/bull and bull are in package.json but BullModule is never configured. Long-running operations - Cloudinary image uploads, email notifications, and Stellar blockchain transactions - currently block the HTTP request thread. A slow Cloudinary upload or Stellar network delay causes the entire request to time out.

Proposed Solution

1. Configure BullModule.forRootAsync() in AppModule with Redis connection from ConfigService
2. Create a QueueModule with processors for:
   • image-upload queue: moves Cloudinary uploads out of the request handler
   • notification queue: placeholder for future email/push notifications
   • blockchain queue: placeholder for Stellar transaction submission
3. POST /api/cloudinary/upload enqueues a job and returns { jobId } immediately
4. Add GET /api/admin/queue/stats (admin-only) returning { waiting, active, completed, failed, delayed }

Acceptance Criteria

• POST /api/cloudinary/upload returns within 200ms regardless of Cloudinary latency
• Job status can be polled via GET /api/admin/queue/stats
• Failed jobs after 3 retries update the related record status to FAILED
• GET /api/admin/queue/stats returns 403 for non-admin users
• BullMQ uses Redis (not in-memory) so jobs survive server restart

[funds0033-cmyk]

pls i would like to work on this i have the skillset to deliver your request flawlessly kindly assign it to me

[funds0033-cmyk]

pls i would like to work on this i have the skillset to deliver your request flawlessly kindly assign it to me

[Senorespecial]

I would really like to work on this issue, please assign.