feat(ui): rebuild homepage with new sections and i18n

This commit introduces a complete overhaul of the homepage, rebuilding it from the ground up with Nuxt UI and full
internationalization support. The new design better showcases the studio's capabilities and projects.

- Re-architected the index page with multiple new sections: Capabilities, Featured Projects, Tech Stack, and Why Choose Us.
- Implemented full i18n for English (en-US) and Chinese (zh-CN) across all new content.
- Centralized the page structure into a `default.vue` layout with a global header (including color mode and locale selectors) and
footer.
- Replaced placeholder logos with a dynamic `UMarquee` of technology icons using Iconify.

app/layouts/default.vue

@@ -1,13 +1,31 @@
 <template>
-  <div>
-    <slot />
-  </div>
+  <UPage>
+    <UHeader>
+      <template #title> Tootaio Studio </template>
+      <template #right>
+        <UColorModeButton />
+        <ULocaleSelect
+          :model-value="locale"
+          :locales="[en, zh_cn]"
+          @update:model-value="(v) => setLocale(v as 'en' | 'zh-CN')"
+        />
+      </template>
+    </UHeader>
+    <UMain>
+      <slot />
+    </UMain>
+    <UFooter>
+      <template #left>
+        &copy; {{ new Date().getFullYear() }} Tootaio Studio. All rights
+        reserved.
+      </template>
+    </UFooter>
+  </UPage>
 </template>
 
 <script lang="ts" setup>
-
+import { en, zh_cn } from "@nuxt/ui/locale";
+const { locale, setLocale } = useI18n();
 </script>
 
-<style>
-
-</style>
+<style></style>