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.

nuxt.config.ts

@@ -36,13 +36,13 @@ export default defineNuxtConfig({
         code: "en",
         iso: "en-US",
         name: "English",
-        files: ["en-US/index.json"],
+        files: ["en-US/common.json", "zh-CN/index.json"],
       },
       {
         code: "zh-CN",
         iso: "zh-CN",
         name: "简体中文",
-        files: ["zh-CN/index.json"],
+        files: ["zh-CN/common.json", "zh-CN/index.json"],
       },
     ],
     strategy: "no_prefix"