Stage 9: Wiring — Start worker, inject into app

[bakhterets]

Wire the notification worker and publisher into the main application.

Files: cmd/main.go, internal/app/app.go

Tasks:

• Build worker with the existing *db.DB (shared pool, no new pool).
• Inject publisher into API and checker.
• Add worker to graceful shutdown.
• Note pod connection budget (max_open_conns_per_pod * max_pods).
• Verify: app boots enabled and disabled; clean shutdown.

Deliverable: Notification system fully integrated into the application lifecycle.

Depends on: Stage 6: API triggers, Stage 7: Checker triggers, Stage*](#)