docs: improve titles

docs/app/pages/[...slug].vue

@@ -23,8 +23,8 @@ const breadcrumb = computed(() => mapContentNavigation(findPageBreadcrumb(naviga
 
 useSeoMeta({
   titleTemplate: '%s - Nuxt UI v3',
-  title: typeof page.value.navigation === 'object' ? page.value.navigation.title : page.value.title,
-  ogTitle: `${typeof page.value.navigation === 'object' ? page.value.navigation.title : page.value.title} - Nuxt UI v3`,
+  title: typeof page.value.navigation === 'object' && page.value.navigation.title ? page.value.navigation.title : page.value.title,
+  ogTitle: `${typeof page.value.navigation === 'object' && page.value.navigation.title ? page.value.navigation.title : page.value.title} - Nuxt UI v3`,
   description: page.value.description,
   ogDescription: page.value.description
 })

docs/content/1.getting-started/2.installation/1.nuxt.md

@@ -1,6 +1,5 @@
 ---
 title: Install in a Nuxt app
-navigation.title: Nuxt
 description: 'Learn how to install and configure Nuxt UI in your Nuxt application.'
 select:
   items:

docs/content/1.getting-started/2.installation/2.vue.md

@@ -1,5 +1,4 @@
 ---
-navigation.title: Vue
 title: Install in a Vue app
 description: 'Learn how to install and configure Nuxt UI in your Vue application.'
 select:

docs/content/1.getting-started/7.i18n/1.nuxt.md

@@ -1,5 +1,4 @@
 ---
-navigation.title: Nuxt
 title: Internationalization (i18n) in a Nuxt app
 description: 'Learn how to internationalize your Nuxt app with multi-directional support (LTR/RTL).'
 select:

docs/content/1.getting-started/7.i18n/2.vue.md

@@ -1,5 +1,4 @@
 ---
-navigation.title: Vue
 title: Internationalization (i18n) in a Vue app
 description: 'Learn how to internationalize your Vue app with multi-directional support (LTR/RTL).'
 select: