preserving navigation

site/src/components/RecordsView.svelte

@@ -1,4 +1,5 @@
 <script lang="ts">
+  import { onMount } from 'svelte';
   import type { AthleteJson } from '../lib/types';
   import { formatDate, sportIcon, sportColor } from '../lib/format';
 
@@ -48,6 +49,20 @@
   ];
 
   let activeTab: SportTab = 'running';
+  let mounted = false;
+
+  $: if (mounted) {
+    const params = new URLSearchParams(window.location.search);
+    if (activeTab === 'running') params.delete('sport'); else params.set('sport', activeTab);
+    const qs = params.toString();
+    history.replaceState(null, '', qs ? `?${qs}` : window.location.pathname);
+  }
+
+  onMount(() => {
+    const sp = new URLSearchParams(window.location.search).get('sport') as SportTab | null;
+    if (sp && TABS.some(t => t.key === sp)) activeTab = sp;
+    mounted = true;
+  });
 
   // Tabs that have at least one record
   function hasRecords(sport: SportTab): boolean {