Express.js Development Error Handler

The `errorhandler` middleware is a development-only utility for Express.js applications, designed to display detailed error information during local development. It is currently at version `1.5.2` and has a slow, maintenance-focused release cadence, primarily addressing dependency updates and minor chores. Its core functionality involves robust content negotiation (HTML, JSON, plain text) to present error stack traces and object details to the client when an error occurs. A key differentiator is its explicit intent for development environments, as it exposes sensitive server-side information, making it unsuitable for production use. It handles both standard `Error` objects and generic JavaScript objects, using `util.inspect` for non-Error objects to provide comprehensive debugging insights.