Delivery worker lifecycle integration

[artugro]

Summary

The DeliveryWorker (background Redis Streams consumer for async message delivery) is implemented but not yet started in the app lifespan.

TODO

1. Start the delivery worker in main.py lifespan alongside the event consumer and scheduler
2. Wire channel service to enqueue deliveries to the worker instead of doing inline HTTP delivery
3. Add integration tests for delivery retry and backoff behavior
4. Add delivery metrics/logging for observability

Files

• src/network/utils/delivery_worker.py — worker implementation
• src/main.py — needs lifespan integration
• src/network/services/channels.py — currently does inline delivery, should optionally enqueue