fix: harden next.config rewrites against wrapper overwrites

apps/web/next.config.mjs

@@ -14,7 +14,7 @@ const nextConfig = {
     'sharp',
     'puppeteer',
     'require-in-the-middle',
-    'import-in-the-middle' // Sentry 10+ instrumentation dependencies
+    'import-in-the-middle'
   ],
   transpilePackages: [
     '@mintel/content-engine',
@@ -37,43 +37,6 @@ const nextConfig = {
       },
     ],
   },
-  async rewrites() {
-    return {
-      beforeFiles: [
-        // Assets requested from root
-        {
-          source: '/assets/:path*',
-          destination: '/showcase/klz-cables.com/assets/:path*',
-        },
-        {
-          source: '/wp-content/:path*',
-          destination: '/showcase/klz-cables.com/assets/klz-cables.com/wp-content/:path*',
-        },
-        {
-          source: '/wp-includes/:path*',
-          destination: '/showcase/klz-cables.com/assets/klz-cables.com/wp-includes/:path*',
-        },
-        // Assets requested relatively from case-studies/work/blog subpages
-        {
-          source: '/:folder(case-studies|work|blog)/assets/:path*',
-          destination: '/showcase/klz-cables.com/assets/:path*',
-        },
-        {
-          source: '/:folder(case-studies|work|blog)/wp-content/:path*',
-          destination: '/showcase/klz-cables.com/assets/klz-cables.com/wp-content/:path*',
-        },
-        {
-          source: '/:folder(case-studies|work|blog)/wp-includes/:path*',
-          destination: '/showcase/klz-cables.com/assets/klz-cables.com/wp-includes/:path*',
-        },
-        // Diagnostic rule
-        {
-          source: '/robots-test',
-          destination: '/robots.txt',
-        },
-      ],
-    };
-  },
   async redirects() {
     return [
       {
@@ -86,7 +49,58 @@ const nextConfig = {
   outputFileTracingRoot: path.join(dirname, '../../'),
 };
 
-const withMDX = createMDX({
-  // Add markdown plugins here, as desired
-});
-export default withPayload(withMintelConfig(withMDX(nextConfig)));
+const withMDX = createMDX({});
+
+// Apply wrappers
+const wrappedConfig = withPayload(withMintelConfig(withMDX(nextConfig)));
+
+// HARDEN REWRITES: Manually merge showcase rules to prevent wrapper overwrites
+const originalRewrites = wrappedConfig.rewrites;
+wrappedConfig.rewrites = async () => {
+  const existing = await originalRewrites?.() || [];
+  
+  // Normalize existing to object pattern (Next.js supports both Array and Object)
+  const normalized = Array.isArray(existing) 
+    ? { afterFiles: existing, beforeFiles: [], fallback: [] } 
+    : existing;
+
+  return {
+    ...normalized,
+    beforeFiles: [
+      ...(normalized.beforeFiles || []),
+      // Diagnostic rule
+      {
+        source: '/robots-test',
+        destination: '/robots.txt',
+      },
+      // Assets requested from root
+      {
+        source: '/assets/:path*',
+        destination: '/showcase/klz-cables.com/assets/:path*',
+      },
+      {
+        source: '/wp-content/:path*',
+        destination: '/showcase/klz-cables.com/assets/klz-cables.com/wp-content/:path*',
+      },
+      {
+        source: '/wp-includes/:path*',
+        destination: '/showcase/klz-cables.com/assets/klz-cables.com/wp-includes/:path*',
+      },
+      // Assets requested relatively from case-studies/work/blog subpages
+      {
+        source: '/:folder(case-studies|work|blog)/assets/:path*',
+        destination: '/showcase/klz-cables.com/assets/:path*',
+      },
+      {
+        source: '/:folder(case-studies|work|blog)/wp-content/:path*',
+        destination: '/showcase/klz-cables.com/assets/klz-cables.com/wp-content/:path*',
+      },
+      {
+        source: '/:folder(case-studies|work|blog)/wp-includes/:path*',
+        destination: '/showcase/klz-cables.com/assets/klz-cables.com/wp-includes/:path*',
+      },
+    ],
+  };
+};
+
+export default wrappedConfig;