Merge remote-tracking branch 'origin/master'

- 替换静态logo设置为动态分类数据获取
- 使用hcTaglib标签库从分类ID 749/707获取图片资源
- 实现图片路径的安全访问（空值合并操作符）
- 统一中英文版本的二维码显示逻辑

public/themes/website/1/en/demo/components/footer.html

@@ -19,7 +19,9 @@
                         <span>Official WeChat</span>
                     </div>
                     <div class="site-footer__qr">
-                        <img src="{hcTaglib:setting name='dark_logo' type='2' /}" alt="Official Channels" />
+                        {hcTaglib:category id="749" item="vo" field="*"}
+                        <img src="{$vo.thumbnail.url ?? ''}" alt="Official Channels" />
+                        {/hcTaglib:category}
                         <span>Official Channels</span>
                     </div>
                 </div>

public/themes/website/1/zh/demo/components/footer.html

@@ -19,7 +19,9 @@
                         <span>官方微信</span>
                     </div>
                     <div class="site-footer__qr">
-                        <img src="{hcTaglib:setting name='dark_logo' type='2' /}" alt="官方视频号" />
+                        {hcTaglib:category id="707" item="vo" field="*"}
+                        <img src="{$vo.thumbnail.url ?? ''}" alt="官方视频号" />
+                        {/hcTaglib:category}
                         <span>官方视频号</span>
                     </div>
                 </div>