Reusable Spring Boot 4 Error Handler

Why use this library Out of the box, Spring Boot returns a plain 500 Internal Server Error for most unhandled exceptions, and its default BasicErrorController produces a flat JSON object that varies between Spring versions and reveals internal details such as exception class names and stack-trace snippets. This makes it hard for API clients to handle errors programmatically and exposes information that should stay server-side. This library replaces that behaviour with a single, consistent error