connect to server on client startup

src/App.svelte

@@ -1,4 +1,6 @@
 <script lang="ts">
+  import { onMount } from 'svelte';
+
   let serverAddress = 'http://127.0.0.1:8787';
   let connectionState = 'OFFLINE';
   let serverVersion = '—';
@@ -843,6 +845,10 @@
       oauthError = 'Copy was unavailable. Select and copy the link manually.';
     });
   }
+
+  onMount(() => {
+    void checkServer();
+  });
 </script>
 
 <svelte:head><title>Trixie</title></svelte:head>