Handle edge cases in search

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

**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 the core notification or search entry points; the issue names no files or tests. Confirm how a new enable_notifications option should affect core notifications, verify its default is false, and add or update tests for the expected behavior once that scope is established.

Written by the indexing model from the issue text.