Api Error Handling

A solid foundation for production API error handling with standardized JSON responses, proper status codes, and request tracing. Includes a custom error class with static helpers for common scenarios, a global Express middleware handler, and a circuit breaker implementation for dealing with flaky downstream services. The code is opinionated in the right ways: shields users from stack traces, separates client from server errors, and includes request IDs for debugging. If you're tired of inconsistent error formats across your endpoints or need to add resilience patterns without reinventing the wheel, this gives you the scaffolding. Python Flask examples are included in the references.