Add TypeScript types for middleware

**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.

Start by locating the middleware and controller entry points in the repository and determine whether the requested change is TypeScript type coverage or more descriptive controller errors. Check the existing type definitions, error-handling tests, and current error messages before defining the expected behavior; done should mean the intended middleware types or error details are documented by passing tests.

Written by the indexing model from the issue text.