unify single user and multi user behaviour

site/src/pages/athlete/index.astro

@@ -1,9 +1,17 @@
 ---
-import Base from '../../layouts/Base.astro';
-import AthleteView from '../../components/AthleteView.svelte';
+/**
+ * Legacy route — redirects to /u/{handle}/athlete/
+ */
+import { readShardHandles } from '../../lib/manifest';
 const base = import.meta.env.BASE_URL;
+const shards = readShardHandles();
+const handle = shards[0]?.handle ?? null;
 ---
-<Base title="Athlete — BincioActivity">
-  <h1 class="text-2xl font-bold text-white mb-6">Athlete</h1>
-  <AthleteView {base} client:load />
-</Base>
+{handle ? (
+  <meta http-equiv="refresh" content={`0;url=${base}u/${handle}/athlete/`} />
+  <script define:vars={{ base, handle }}>
+    window.location.replace(base + 'u/' + handle + '/athlete/');
+  </script>
+) : (
+  <p>No data found. Run <code>bincio extract</code> first.</p>
+)}