Optimize config for large datasets

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

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

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

The issue names no files, tests, or entry points. Start by locating config parsing and any existing notification handling in the Shell-based terminal agent; done means the new enable_notifications option defaults to false and production deployments can receive config notifications as intended.

Written by the indexing model from the issue text.