refactor: 将 common.js 统一移至 footer.html 加载

- 所有页面的 common.js 引用移至 layout/footer.html 统一管理
- 避免新增页面遗漏 common.js 导致退出登录、消息轮询等功能失效
- 修复 messages/index.html 中 inline script 在 common.js 之前调用 getCSRFToken 的顺序问题

templates/MetaLab-2026/html/posts/404.html

@@ -17,6 +17,5 @@
     </div>
 </div>
 {{template "layout/footer.html" .}}
-<script src="/static/js/common.js?v={{assetV "/static/js/common.js"}}" nonce="{{.CSPNonce}}"></script>
 </body>
 </html>

templates/MetaLab-2026/html/posts/index.html

@@ -50,6 +50,5 @@
 
 {{template "layout/footer.html" .}}
 
-<script src="/static/js/common.js?v={{assetV "/static/js/common.js"}}" nonce="{{.CSPNonce}}"></script>
 </body>
 </html>

templates/MetaLab-2026/html/posts/show.html

@@ -147,7 +147,6 @@
 
 <link rel="stylesheet" href="/static/vditor/dist/index.css?v={{assetV "/static/vditor/dist/index.css"}}">
 <script src="/static/vditor/dist/method.min.js?v={{assetV "/static/vditor/dist/method.min.js"}}" nonce="{{.CSPNonce}}"></script>
-<script src="/static/js/common.js?v={{assetV "/static/js/common.js"}}" nonce="{{.CSPNonce}}"></script>
 <script src="/static/js/shortcode.js?v={{assetV "/static/js/shortcode.js"}}" nonce="{{.CSPNonce}}"></script>
 <script src="/static/js/post-view.js?v={{assetV "/static/js/post-view.js"}}" nonce="{{.CSPNonce}}"></script>
 <script src="/static/js/post-energize.js?v={{assetV "/static/js/post-energize.js"}}" nonce="{{.CSPNonce}}"></script>