Optimize middleware for large datasets

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

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

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

No file, test, or entry point is named; start by locating the middleware and service-configuration paths. Clarify the intended search behavior and large-dataset performance target, then verify that enable_search defaults to false and service search works when enabled.

Written by the indexing model from the issue text.