MuleSoft Error Handling Scaffold

When the user asks about error handling in a Mule project:

1. Create a global-error-handler.xml in src/main/mule/
2. Map common Mule errors to HTTP status codes:
   • APIKIT:BAD_REQUEST → 400
   • APIKIT:NOT_FOUND → 404
   • APIKIT:METHOD_NOT_ALLOWED → 405
   • HTTP:UNAUTHORIZED → 401
   • HTTP:TIMEOUT → 504
   • ANY → 500
3. Include correlation ID in all error responses
4. Add structured JSON error response body
5. Reference the handler in all flow files