refactor(admin): simplify entry route to point to dashboard

The `/admin` route now directly serves the dashboard page by adding an alias, removing the need for a separate login page at that path.

- Deletes `pages/admin/index.vue` and the `admin-login` layout.
- Aliases `/admin` to `/admin/dashboard` for a more direct entry point.
- Improves the default layout with a sticky footer.
- Updates VSCode settings for better Tailwind CSS IntelliSense.

app/layouts/default.vue

@@ -1,10 +1,10 @@
 <template>
-  <div>
+  <div class="min-h-screen flex flex-col">
     <!-- 导航栏 -->
     <header class="bg-white shadow-md sticky top-0 z-50">
       <div class="max-w-6xl mx-auto px-4 py-3 flex justify-between items-center">
         <div>
-          <img class="inline w-16" src="/Logo.svg" alt="YPHS Alumni">
+          <img class="inline w-16" src="/Logo.svg" alt="YPHS Alumni" />
           <h1 class="inline text-xl font-bold text-gray-900">
             <a href="/" class="ml-4 hover:text-primary">永平中学校友会</a>
           </h1>
@@ -19,22 +19,23 @@
             加入
             <Icon name="mdi:account-plus" class="w-5 h-5" />
           </a>
-
         </nav>
       </div>
     </header>
 
-    <slot />
+    <!-- 主体部分 -->
+    <main class="flex-1">
+      <slot />
+    </main>
 
     <!-- 页脚 -->
     <footer class="bg-gray-900 text-gray-300 py-6">
       <div class="max-w-6xl mx-auto px-4 flex flex-col md:flex-row justify-between items-center">
-        <!-- 左侧版权信息 -->
         <div class="text-center md:text-left">
           <p>© 2025 永平中学校友会. 保留所有权利.</p>
         </div>
 
-        <div class="">
+        <div>
           <p class="mt-1">
             Powered by:
             <a href="https://tootaio.com" target="_blank" class="font-semibold hover:underline" style="color: #e24545;">
@@ -44,7 +45,6 @@
           </p>
         </div>
 
-        <!-- 右侧社交链接 -->
         <div class="flex space-x-4 mt-3 md:mt-0">
           <a href="#">
             <Icon name="mdi-facebook" />
@@ -60,9 +60,3 @@
     </footer>
   </div>
 </template>
-
-<script lang="ts" setup>
-
-</script>
-
-<style></style>