Add TypeScript types for config

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

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

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

Start by locating the configuration definitions and the TypeScript-related error-handling entry points. Read how configuration types and errors are currently represented, then verify that the completed change provides descriptive error messages and covers the configuration typing requested by the issue.

Written by the indexing model from the issue text.