fix(footer): point Shard Status link to /site/shard

The footer's "Shard Status" link targeted /site/status; point it at the
richer live shard page at /site/shard.

Co-Authored-By: Claude <noreply@anthropic.com>

client/src/components/SiteFooter.jsx

@@ -37,7 +37,7 @@ export default function SiteFooter() {
               {contactEmail}
             </a>
             &nbsp;·&nbsp;
-            <Link to="/site/status" style={{ color: 'var(--accent)', textDecoration: 'none' }}>
+            <Link to="/site/shard" style={{ color: 'var(--accent)', textDecoration: 'none' }}>
               Shard Status
             </Link>
             &nbsp;·&nbsp;