Refactor controllers for better readability

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

**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 handling and store-related notification entry points in the repository; the issue names no files or tests. Determine the expected notification behavior and integration boundaries before implementing the enable_notifications option, with false as its default and production store notifications working when enabled.

Written by the indexing model from the issue text.