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.

content/en-US/index.yml

@@ -28,6 +28,7 @@ featuredProjects:
       description: "An interactive guide which help more than 5000 students back to China Mainland to continue their study during pandemic COVID-19 in year 2022. This project is supported by The Ministry of Foreign Affairs (MFA) in Malaysia"
       image: "http://img.tootaio.com/i/2025/11/05/d9kcma.png"
       demoLink: "https://tootaio.github.io"
+      spotlight: true
     - title: "Light Chasing"
       description: "This is an entry from the 2023 G-bits University GameJam Challenge, based on the Godot engine."
       image: "https://img.tootaio.com/i/2025/09/26/j2swgq.png"