Add unit tests for handlers

**Description**
Currently auth lacks proper backup support.

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

**Priority**: Low/Medium

The issue names authentication handlers but gives no file or test path. Start by locating the handlers and existing unit-test setup, then determine the intended configurable backup behavior and sensible defaults. Done means the backup behavior is implemented and covered by handler tests.

Written by the indexing model from the issue text.