Update middleware documentation

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

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

**Priority**: Low/Medium

Start by locating the middleware and routes entry points in the repository, then trace how route handling currently works and whether any search support exists. Clarify the configurable search behavior and sensible defaults before implementation; done means routes support the agreed search configuration and related checks pass.

Written by the indexing model from the issue text.