feat(#165): Implement BullMQ module setup

Create BullMQ module that shares the existing Valkey connection for job queue processing.

Files Created:
- apps/api/src/bullmq/bullmq.module.ts - Global module configuration
- apps/api/src/bullmq/bullmq.service.ts - Queue management service
- apps/api/src/bullmq/queues.ts - Queue name constants
- apps/api/src/bullmq/index.ts - Barrel exports
- apps/api/src/bullmq/bullmq.service.spec.ts - Unit tests

Files Modified:
- apps/api/src/app.module.ts - Import BullMqModule

Queue Definitions:
- mosaic-jobs (main queue)
- mosaic-jobs-runner (read-only operations)
- mosaic-jobs-weaver (write operations)
- mosaic-jobs-inspector (validation operations)

Implementation:
- Reuses VALKEY_URL from environment (shared connection)
- Follows existing Valkey module patterns
- Includes health check methods
- Proper lifecycle management (init/destroy)
- Queue names use hyphens instead of colons (BullMQ requirement)

Quality Gates:
- Unit tests: 11 passing
- TypeScript: No errors
- ESLint: No violations
- Build: Successful

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docs/scratchpads/165-bullmq-module-setup.md

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+# Issue #165: BullMQ Module Setup
+
+## Objective
+
+Create BullMQ module that shares the existing Valkey connection for job queue processing.
+
+## Approach
+
+1. Examine existing Valkey configuration patterns
+2. Write tests for BullMQ module (TDD - RED)
+3. Implement BullMQ module components
+4. Integrate with app.module.ts
+5. Run quality gates
+
+## Progress
+
+- [x] Create scratchpad
+- [x] Examine existing Valkey configuration
+- [x] Write unit tests (RED phase)
+- [x] Create queue definitions
+- [x] Implement BullMQ service
+- [x] Implement BullMQ module
+- [x] Add to app.module.ts
+- [x] Run quality gates (typecheck, lint, build, test)
+- [x] Commit changes
+
+## Testing
+
+- Unit tests for BullMQ service
+- Queue creation verification
+- Valkey connection validation
+
+## Notes
+
+- Prerequisites: Issue #163 completed (dependencies installed)
+- Must reuse VALKEY_URL from environment
+- Queue naming convention changed from `mosaic:jobs:*` to `mosaic-jobs-*` (BullMQ doesn't allow colons)
+- Unit tests pass without requiring Redis connection (tests validate configuration and structure)
+- All quality gates passed: typecheck, lint, build, test
+
+## Implementation Details
+
+- Created 4 queues: main, runner, weaver, inspector
+- Follows existing Valkey module patterns
+- Uses ioredis connection under the hood (BullMQ requirement)
+- Includes health check methods for monitoring
+- Proper cleanup in onModuleDestroy lifecycle hook