minor improvements:

- page titles
- favicon
- background logo

frontend/src/routes/time/Index.svelte

@@ -142,6 +142,10 @@
     onMount(loadTimes);
 </script>
 
+<svelte:head>
+    <title>Umbrella – {t('timetracking')}</title>
+</svelte:head>
+
 <h1>{t('timetracking')}</h1>
 {#if error}
 <span class="error">{error}</span>