Optimize auth for large datasets

**Description**
Currently helpers lacks proper pagination support.

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

**Priority**: Low/Medium

The issue names no file or test, so start by locating the helpers responsible for authentication and tracing their callers. Check how large result sets are currently handled, then verify configurable pagination and sensible defaults with the relevant existing tests or a reproducible large-dataset case.

Written by the indexing model from the issue text.