fix vercel load errors

api/_cors.js

@@ -0,0 +1,38 @@
+const LOCALHOST_ORIGIN_PREFIXES = ['http://localhost:', 'http://127.0.0.1:'];
+
+export function isAllowedOrigin(origin) {
+  if (!origin) return false;
+
+  if (LOCALHOST_ORIGIN_PREFIXES.some(prefix => origin.startsWith(prefix))) {
+    return true;
+  }
+
+  try {
+    const url = new URL(origin);
+    if (url.hostname === 'craze-data-check.vercel.app') return true;
+    if (url.hostname.endsWith('.vercel.app')) return true;
+    if (process.env.APP_URL) {
+      const appUrl = new URL(process.env.APP_URL);
+      if (url.hostname === appUrl.hostname) return true;
+    }
+    if (process.env.VERCEL_URL) {
+      const vercelHost = process.env.VERCEL_URL.replace(/^https?:\/\//, '');
+      if (url.hostname === vercelHost) return true;
+    }
+  } catch {
+    return false;
+  }
+
+  return false;
+}
+
+export function applyCors(req, res, methods) {
+  const origin = req.headers.origin;
+  if (isAllowedOrigin(origin)) {
+    res.setHeader('Access-Control-Allow-Origin', origin);
+  }
+  res.setHeader('Access-Control-Allow-Methods', methods);
+  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization, apikey');
+  res.setHeader('Access-Control-Max-Age', '86400');
+  res.setHeader('Vary', 'Origin');
+}