Support filtering configuration

**Feature request**
It would be great to have notifications for services.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_notifications` with default `false`.

Start by locating the configuration parsing and service-notification entry points in the repository, then trace how production service events are currently handled. Define the expected behavior for the new enable_notifications option, including its false default, and verify that notifications remain disabled unless explicitly enabled.

Written by the indexing model from the issue text.