Add TypeScript types for auth

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

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

**Priority**: Low/Medium

Start by locating the middleware entry point and the existing authentication-related TypeScript definitions. Clarify whether the intended change is authentication types, configurable search support, or both, then define the expected defaults and verify that middleware search behaves accordingly.

Written by the indexing model from the issue text.