fix(notifications): expose preferences in settings navigation

frontend/components/MainNav.vue

@@ -318,6 +318,11 @@ const links = computed(() => {
   ]
 
   const settingsChildren = [
+    {
+      label: "Benachrichtigungen",
+      to: "/settings/notifications",
+      icon: "i-heroicons-bell",
+    },
     featureEnabled("settingsNumberRanges") ? {
       label: "Nummernkreise",
       to: "/settings/numberRanges",

frontend/pages/settings/notifications.vue

@@ -0,0 +1,9 @@
+<template>
+  <UDashboardNavbar title="Benachrichtigungen" />
+
+  <div class="min-h-0 flex-1 overflow-y-auto p-4 sm:p-6">
+    <UCard class="mx-auto w-full max-w-4xl">
+      <NotificationPreferences />
+    </UCard>
+  </div>
+</template>