Optimize controllers for large datasets

**Description**
Currently lib lacks proper search support.

**Proposed solution**
Add configurable search with sensible defaults.

**Priority**: Low/Medium

No specific files, tests, controllers, or search entry points are named. Start by locating the controller code under lib and tracing how large datasets are currently handled, then determine the intended search behavior and configuration defaults with the maintainers. Done means configurable search works with documented sensible defaults and is covered by relevant tests.

Written by the indexing model from the issue text.