fix: sidebar menu not updating after engine switch + dashboard loading skeleton

1. engine-manager: activateEngine 切换时调用 engine.boot() 检测状态
2. main.js: onEngineChange 监听器重绑 state/ready 回调，确保新引擎
   状态变化时侧边栏自动刷新
3. Hermes 仪表盘: loading 期间显示骨架屏动画，消除空白等待
4. components.css: 新增 .skeleton-line 通用骨架行样式

src/engines/hermes/pages/dashboard.js

@@ -96,6 +96,33 @@ export function render() {
   }
 
   function draw() {
+    // 加载骨架屏
+    if (loading) {
+      el.innerHTML = `
+        <div class="page-header" style="display:flex;align-items:center;gap:12px">
+          <h1 style="margin:0">${t('engine.hermesDashboardTitle')}</h1>
+        </div>
+        <div style="display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:16px;margin-bottom:20px">
+          ${[1,2,3,4].map(() => `<div class="card"><div class="card-body" style="padding:16px">
+            <div class="skeleton-line" style="width:60%;height:12px;margin-bottom:10px"></div>
+            <div class="skeleton-line" style="width:80%;height:20px"></div>
+          </div></div>`).join('')}
+        </div>
+        <div class="card" style="margin-bottom:20px"><div class="card-body" style="padding:20px">
+          <div class="skeleton-line" style="width:40%;height:16px;margin-bottom:16px"></div>
+          <div style="display:flex;gap:6px;margin-bottom:14px">${[1,2,3,4].map(() => '<div class="skeleton-line" style="width:60px;height:24px;border-radius:12px"></div>').join('')}</div>
+          <div style="display:grid;grid-template-columns:1fr 1fr;gap:12px">
+            <div class="skeleton-line" style="height:36px"></div>
+            <div class="skeleton-line" style="height:36px"></div>
+          </div>
+        </div></div>
+        <div class="card" style="margin-bottom:20px"><div class="card-body" style="padding:16px">
+          <div class="skeleton-line" style="width:120px;height:32px;border-radius:6px"></div>
+        </div></div>
+      `
+      return
+    }
+
     const gwRunning = info?.gatewayRunning
     const port = info?.gatewayPort || 8642
     const version = info?.version || '-'

src/lib/engine-manager.js

@@ -88,6 +88,13 @@ export async function activateEngine(id, persist = true) {
     setDefaultRoute(engine.getDefaultRoute())
   }
 
+  // 切换时启动新引擎（检测安装状态等），初始化由 main.js 处理
+  if (persist && engine.boot) {
+    try { await engine.boot() } catch (e) {
+      console.warn('[engine-manager] boot 失败:', e)
+    }
+  }
+
   // 持久化到 clawpanel.json
   if (persist) {
     try {

src/main.js

@@ -370,6 +370,28 @@ async function boot() {
       }).catch(() => {})
     : Promise.resolve()
 
+  // --- 引擎状态监听管理 ---
+  let _engineStateUnsub = null
+  let _engineReadyUnsub = null
+  function bindEngineListeners(engine) {
+    // 清理旧监听
+    if (_engineStateUnsub) { _engineStateUnsub(); _engineStateUnsub = null }
+    if (_engineReadyUnsub) { _engineReadyUnsub(); _engineReadyUnsub = null }
+    // 注册新监听
+    if (engine.onStateChange) {
+      _engineStateUnsub = engine.onStateChange(() => renderSidebar(sidebar))
+    }
+    if (engine.onReadyChange) {
+      _engineReadyUnsub = engine.onReadyChange(() => renderSidebar(sidebar))
+    }
+  }
+
+  // 引擎切换时：重新绑定状态监听 + 刷新侧边栏
+  onEngineChange((engine) => {
+    bindEngineListeners(engine)
+    renderSidebar(sidebar)
+  })
+
   ensureWebSession.then(() => getActiveEngineId() === 'openclaw' ? loadActiveInstance() : Promise.resolve()).then(async () => {
     const engine = getActiveEngine()
     if (!engine) return
@@ -381,12 +403,7 @@ async function boot() {
     renderSidebar(sidebar)
 
     // 监听引擎状态变化（如 setup 完成后 ready 变为 true），自动刷新侧边栏
-    if (engine.onStateChange) {
-      engine.onStateChange(() => renderSidebar(sidebar))
-    }
-    if (engine.onReadyChange) {
-      engine.onReadyChange(() => renderSidebar(sidebar))
-    }
+    bindEngineListeners(engine)
 
     if (!engine.isReady()) {
       setDefaultRoute(engine.getSetupRoute())

src/style/components.css

@@ -31,6 +31,12 @@
   0% { background-position: 200% 0; }
   100% { background-position: -200% 0; }
 }
+.skeleton-line {
+  background: linear-gradient(90deg, var(--bg-secondary) 25%, var(--bg-tertiary, var(--bg-card-hover)) 50%, var(--bg-secondary) 75%);
+  background-size: 200% 100%;
+  animation: skeleton-shine 1.4s ease infinite;
+  border-radius: 4px;
+}
 
 /* 卡片 */
 .card {