refactor(middleware): upgrade locale redirects from 307 to 308 for better scanner compatibility

middleware.ts

@@ -62,6 +62,17 @@ export default function middleware(request: NextRequest) {
   try {
     // Apply internationalization middleware
     const response = intlMiddleware(effectiveRequest);
+
+    // Upgrade 307 (Temporary Redirect) to 308 (Permanent Redirect)
+    // This improves compatibility with scanners (Website Carbon, PageSpeed) and SEO.
+    if (response.status === 307) {
+      const location = response.headers.get('Location');
+      if (location) {
+        const url = new URL(location, request.url);
+        return Response.redirect(url, 308);
+      }
+    }
+
     return response;
   } catch (error) {
     console.error(