Add unit tests for auth

**Description**
Currently data lacks proper notifications support.

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

**Priority**: Low/Medium

The title asks for auth unit tests, while the description proposes configurable notifications, so first clarify which work is intended. No files, tests, or entry points are named; after the scope is confirmed, locate the relevant auth or notification behavior and its existing tests. Done means the agreed behavior is implemented and covered by unit tests.

Written by the indexing model from the issue text.