fix: restore webapp list visibility on page switch

app/src/main/assets/h5/js/router.js

@@ -33,6 +33,9 @@ const router = {
     if (topbar) topbar.style.display = 'none';
     const tabPanel = document.getElementById('tab-panel');
     if (tabPanel) tabPanel.style.display = 'none';
+    // 移除 webapp-active：webapp 已丢后台，恢复 webapp 列表显示
+    // Remove webapp-active: the webapp is backgrounded, restore the list display
+    document.body.classList.remove('webapp-active');
     // 非首页时侧边栏顶部显示小时间（容器始终占位，仅切换可见性避免撑动图标）
     // Show the small clock at the sidebar top when not on home (the container
     // always occupies space; only toggle visibility to avoid shifting icons)