Problem#

All in-process events (task.updated, task.stuck, job.created/completed/failed, artefacts.synced) still used the in-process EventEmitter2 bus, making them invisible to horizontally-scaled workers and inaccessible via Redis. This blocked AW-1's multi-worker architecture from receiving real-time pipeline state changes.

Task / Link#

Closes #444 — AW-8: Migrate EventEmitter2 events to EventBusService

Depends on #443 (AW-7: EventBusService backed by Redis) — merged into this branch.

Changes#

• R1 (task.updated): TaskStateService emits via EventBusService; WsGatewayService and MetricsCache register handlers via eventBus.on() in onModuleInit
• R2 (task.stuck): WatchdogService emits via EventBusService
• R3 (artefacts.synced): PhaseRouterService emits via EventBusService
• R4 (job.completed/job.failed): SqliteJobQueue emits via EventBusService
• R5 (job.created): Replace 3× self-trigger emits with direct void this.processNext() calls; Redis emit added for multi-instance support
• R6 (cleanup): npm uninstall @nestjs/event-emitter; all EventEmitterModule.forRoot() and EventEmitter2 imports removed
• All spec/integration/e2e files updated to use EventBusService mocks

Notes#

• All eventBus.emit() calls are wrapped in try/catch to avoid breaking pipeline if Redis publish fails
• The job.created self-trigger migration (R5) uses direct processNext() call — simpler and more reliable than pub/sub for single-instance; Redis emit future-proofs multi-instance
• Unit tests for SqliteJobQueue adjusted: enqueue now directly calls processNext, tests register handler after enqueue to avoid race conditions

Testing#

• npm run lint — passed (zero warnings)
• npm run test — 807/807 tests passed