Improve error messages in store

**Problem**
When working with routes, 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 store and route-handling entry points, then inspect the existing error paths and their current messages. Clarify which failures need more detail and how the wording should help debugging; done means the relevant route errors are descriptive and covered by the repository's existing checks.

Written by the indexing model from the issue text.