feat: h5 desktop shell with sidebar and dark mode

- tokens.css/app.css: Miuix dual-color tokens + HyperOS 4 soft-glass rail
- bridge.js/router.js: Promise bridge wrapper + 5-page router with top clock
- index.html: sidebar + 5 page containers
- native wallpaper transparency: Theme.Hearth (showWallpaper + transparent window) + WebView transparent background

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

@@ -0,0 +1,25 @@
+// 桌面路由：侧边栏 5 页 + 页面切换 + 顶部时间
+// Launcher router: 5 sidebar pages + page switching + top clock
+const PAGES = [
+  { id: 'home', label: '首页', icon: '🏠' },
+  { id: 'immersive', label: '沉浸首页', icon: '🚗' },
+  { id: 'webapplist', label: 'H5 应用', icon: '🌐' },
+  { id: 'applist', label: '安卓 APP', icon: '📱' },
+  { id: 'settings', label: '设置', icon: '⚙️' },
+];
+
+const router = {
+  current: 'home',
+  navigate(id) {
+    this.current = id;
+    document.querySelectorAll('[data-page]').forEach(el =>
+      el.classList.toggle('active', el.dataset.page === id));
+    // 非首页时侧边栏顶部显示小时间
+    // Show the small clock at the sidebar top when not on home
+    const clock = document.getElementById('rail-clock');
+    if (clock) clock.style.display = (id === 'home') ? 'none' : 'block';
+    if (id === 'home') window.updateHomeCards && window.updateHomeCards();
+    if (id === 'applist') window.loadAppList && window.loadAppList();
+    if (id === 'webapplist') window.loadWebAppList && window.loadWebAppList();
+  }
+};