Add TypeScript types for auth

**Problem**
When working with controllers, the error messages could be more descriptive.

**Suggestion**
Improve error handling and add detailed error messages.

**Context**
This would help with debugging and maintenance.

No files, tests, or entry points are named. Start by reconciling the title's request for TypeScript auth types with the body’s request for more descriptive controller errors, then identify the affected controller and authentication code. Done should include a specific agreed scope and tests or examples covering the new types or error messages.

Written by the indexing model from the issue text.