Title#

feat: implement BullMQ job queue driver behind JOB_QUEUE_DRIVER config flag

Problem#

The job queue is backed by SQLite, which limits scalability and reliability. AW-11 introduces a BullMQ/Redis-backed implementation that can be switched in at runtime without breaking the existing SQLite path.

Task / Link#

Closes #457

Changes#

• Add JOB_QUEUE_DRIVER Joi validation to config.schema.ts (valid: sqlite | bullmq, default: sqlite)
• Create BullMQJobQueue implementing the JobQueue interface using BullMQ Queue + Worker
• Lazy Redis connection: Queue and Worker are only instantiated when first used, so driver=sqlite never opens a Redis connection
• Per-issue concurrency control via in-memory activeIssues Set; BullMQ concurrency: 1 ensures sequential processing
• Update QueueModule factory provider to select BullMQJobQueue or SqliteJobQueue based on JOB_QUEUE_DRIVER
• Export BullMQJobQueue from the queue index

Notes#

• BullModule.forRootAsync is NOT added to QueueModule — BullMQJobQueue manages its own IORedis connections directly, matching the lazy-init design and avoiding module-level conflicts with InvokeModule. This remains a follow-up for AW-3 (#439).
• Both queue implementations are registered as providers; lazy init prevents Redis connections when using the SQLite driver.

Testing#

• 13 new unit tests in bullmq-job-queue.spec.ts covering: enqueue, onJob/worker init, per-issue dedup, error handling, and onModuleDestroy cleanup
• Full test suite: 824 tests pass
• Lint: zero warnings