feat(app): introduce Hall of Fame section and refactor UI

This commit adds the '名人堂' (Hall of Fame) feature and removes the Element Plus dependency.

- feat(content): Add Hall of Fame section with a new content collection, homepage component, and detail pages.
- refactor(join-us): Rewrite the 'Join Us' form to remove Element Plus, using native elements and Reka UI. The form is
temporarily disabled.
- feat(ui): Display cover images on News and Events cards.
- chore: Integrate Umami for web analytics.
- fix: Correct minor text issues, including graduation year in the footer.

app/components/index/Donate.vue

@@ -2,7 +2,7 @@
   <div>
     <!-- 捐赠模块 -->
     <section id="donate" class="py-16 text-center bg-[var(--color-primary)]">
-      <h3 class="text-2xl font-bold text-gray-900 mb-4">支持与捐赠</h3>
+      <h3 class="text-2xl font-bold text-gray-900 mb-4">支持与捐赠（功能未开放）</h3>
       <p class="max-w-2xl mx-auto text-gray-700 mb-6">您的捐赠将用于奖学金、校园建设及校友活动发展。感谢您对母校的支持！</p>
       <a href="#" class="bg-[var(--color-secondary)] text-white px-8 py-3 rounded-xl shadow hover:opacity-90">立即捐赠</a>
     </section>