Add and wire extended site env config

components/site-footer.tsx

@@ -1,9 +1,55 @@
 import { siteConfig } from '@/lib/config';
 
 export function SiteFooter() {
+  const { social } = siteConfig;
+
   return (
     <footer className="border-t py-4 text-center text-sm text-gray-500">
-      © {new Date().getFullYear()} {siteConfig.author}
+      <div>
+        © {new Date().getFullYear()} {siteConfig.author}
+      </div>
+      {(social.github || social.twitter || social.linkedin || social.email) && (
+        <div className="mt-1 space-x-3">
+          {social.github && (
+            <a
+              href={social.github}
+              target="_blank"
+              rel="noopener noreferrer"
+              className="hover:underline"
+            >
+              GitHub
+            </a>
+          )}
+          {social.twitter && (
+            <a
+              href={`https://twitter.com/${social.twitter.replace('@', '')}`}
+              target="_blank"
+              rel="noopener noreferrer"
+              className="hover:underline"
+            >
+              Twitter
+            </a>
+          )}
+          {social.linkedin && (
+            <a
+              href={social.linkedin}
+              target="_blank"
+              rel="noopener noreferrer"
+              className="hover:underline"
+            >
+              LinkedIn
+            </a>
+          )}
+          {social.email && (
+            <a
+              href={`mailto:${social.email}`}
+              className="hover:underline"
+            >
+              Email
+            </a>
+          )}
+        </div>
+      )}
     </footer>
   );
 }