feat(ui): implement dynamic dropdown navigation and refactor project cards

Replaced the static navigation with a dynamic, internationalized dropdown menu powered by a new `useNavLinks` composable. The
navigation items are now sourced from i18n files. The featured project cards on the homepage have been refactored to use the
`<UPageCard>` component, and the content schema is updated with `spotlight` and `highlight` options for enhanced display.

app/layouts/default.vue

@@ -1,9 +1,19 @@
 <template>
   <UPage>
-    <UHeader>
+    <UHeader
+      :ui="{
+        left: 'flex items-center gap-1.5',
+        center: 'hidden lg:flex lg:flex-16',
+        right: 'flex items-center justify-end gap-1.5',
+      }"
+    >
       <template #title> Tootaio Studio </template>
       <template #default>
-        <UNavigationMenu :items="navLinks" variant="link" />
+        <UNavigationMenu
+          :items="navLinks"
+          variant="link"
+          class="w-full justify-center"
+        />
       </template>
       <template #body>
         <UNavigationMenu :items="navLinks" orientation="vertical" />
@@ -42,6 +52,7 @@
 
 <script lang="ts" setup>
 const { setLocale } = useI18n();
+const navLinks = useNavLinks();
 </script>
 
 <style></style>