chore: remove active_admin.js and add analytics scripts

- Removed the active_admin.js file from the project as it is no longer needed.
- Added the Busuanzi site statistics script to the application layout for
  tracking page views and visitors.
- Updated the footer layout to include site statistics, providing users
  with real-time view and visitor counts.

These changes streamline the asset management by removing unused files and
integrate site analytics directly into the footer for better visibility.

app/assets/javascripts/active_admin.js

@@ -1,2 +0,0 @@
-//= require active_admin/base
-import "@activeadmin/activeadmin";

app/views/layouts/application.html.erb

@@ -35,6 +35,8 @@
     <%= stylesheet_link_tag "application", "data-turbo-track": "reload" %>
     <script defer data-domain="todayaiweather.com" src="https://plausible.frytea.com/js/script.js"></script>
 
+    <script defer src="https://busuanzi.frytea.com/js"></script>
+
     <!-- Google tag (gtag.js) -->
     <script async src="https://www.googletagmanager.com/gtag/js?id=G-PX1C92V5L7"></script>
     <script>
@@ -73,11 +75,22 @@
 
   <!-- 页脚 -->
   <footer class="footer footer-center p-8 bg-base-200 text-base-content">
-    <div class="container mx-auto">
+    <div class="container mx-auto flex flex-col gap-2">
+      <!-- 站点统计 -->
+      <div class="text-sm opacity-70">
+      <span class="mx-2">
+        <i class="fas fa-eye"></i> Views: <span id="busuanzi_value_site_pv">...</span>
+      </span>
+        <span class="mx-2">
+        <i class="fas fa-user"></i> Visitors: <span id="busuanzi_value_site_uv">...</span>
+      </span>
+      </div>
+
       <p class="font-display opacity-80">
         Copyright © 2024 - All rights reserved by AI Weather Art
       </p>
     </div>
   </footer>
+
   </body>
 </html>