feat(admin): add initial admin dashboard structure

This commit introduces the foundational structure for the new admin dashboard.

- Utilizes @nuxt/ui to build the dashboard layout, including a collapsible sidebar and navigation.
- Adds initial pages for the dashboard, news, events, and hall of fame management.
- Implements a composable `useDashboardSidebarLinks` for managing sidebar navigation.
- Refactors the default layout by integrating the header and footer directly.
- Swaps the primary and secondary theme colors across the application.

app/components/index/Events.vue

@@ -11,7 +11,7 @@
               <h4 class="font-semibold text-lg mb-2">{{ event.title }}</h4>
               <p class="text-sm text-gray-600 mb-1">日期：{{ useChineseDateFormat(event.date) }}</p>
               <p class="text-sm text-gray-600 mb-4">地点：{{ event.location }}</p>
-              <a :href="event.path" class="bg-secondary text-white px-5 py-2 rounded-lg hover:opacity-90">阅读详情</a>
+              <a :href="event.path" class="bg-primary text-white px-5 py-2 rounded-lg hover:opacity-90">阅读详情</a>
             </div>
           </div>
         </div>