Add TypeScript types for components

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

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

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

The issue title requests TypeScript types for components, while the body requests more descriptive authentication error messages and does not name files or tests. First locate the authentication error-handling entry points and existing component type definitions, then clarify which change is intended. Done means the agreed scope is implemented with coverage for the affected behavior.

Written by the indexing model from the issue text.