fix: athlete page shows empty state instead of error when athlete.json missing

site/src/components/AthleteView.svelte

@@ -42,8 +42,7 @@
         loadAthlete(import.meta.env.BASE_URL, athleteUrl || undefined),
         loadIndex(import.meta.env.BASE_URL, indexUrl || undefined),
       ]);
-      if (!athleteData) throw new Error('athlete.json not found — run bincio extract first');
-      athlete = athleteData;
+      athlete = athleteData as AthleteJson | null;
       activities = index.activities.filter(a => a.mmp && a.privacy !== 'private');
     } catch (e: any) {
       error = e.message;
@@ -78,7 +77,17 @@
   <p class="text-zinc-400 text-sm">Loading…</p>
 {:else if error}
   <p class="text-red-400 text-sm">{error}</p>
-{:else if athlete}
+{:else if !athlete}
+  <div class="text-zinc-400 text-sm space-y-3">
+    <p>No athlete profile yet.</p>
+    {#if editEnabled}
+      <button
+        on:click={() => drawerOpen = true}
+        class="px-3 py-1.5 text-xs border border-zinc-700 hover:border-zinc-500 text-zinc-400 hover:text-white rounded-md transition-colors"
+      >Create profile</button>
+    {/if}
+  </div>
+{:else}
 
   <!-- Header row: tabs + edit button -->
   <div class="flex items-center justify-between mb-6 border-b border-zinc-800 pb-0">