querying non-existing GraphQL API endpoint causes error in console

We had an old endpoint. configured, that no longer exists (`https://app.staging.graphql-hive.com/graphql`).

When executing against errors are printed to the browser console, but there is no UI feedback that the execution failed.

<img width="1790" height="1170" alt="Image" src="https://github.com/user-attachments/assets/4af9d58e-0033-47d5-a221-b252fca0af9d" />