minor improvements:

- page titles
- favicon
- background logo

frontend/src/routes/user/User.svelte

@@ -12,6 +12,10 @@
     if (redirect && user.name) location.href = redirect;
 </script>
 
+<svelte:head>
+    <title>Umbrella – {t('user')}: {user?.name}</title>
+</svelte:head>
+
 <h1>{t('user_module')}</h1>
 
 <Profile />