Fix Common CORS Errors in APIs and Frontend Apps

I've spent many hours solving this… Cross-Origin Resource Sharing (CORS) errors are a regular part of web development. More info: MDN CORS Guide. Issue 1: No Access-Control-Allow-Origin Header Access to XMLHttpRequest blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. The frontend is calling a backend endpoint without proper CORS configuration. Fix: 'allowed_origins' => [ 'http://localhost:3000', 'http://local...