Improve middleware performance

**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.

Start by locating the middleware and authentication error-handling entry points in the repository. Review how current auth failures are reported, then define the required message details and verify that the resulting errors are more descriptive without disrupting existing behavior.

Written by the indexing model from the issue text.