feat: 全站 PageShell 设计系统与专业 UI 统一

- 新增 PageShell/PageTabs/ContentPanel/PageLoading/PageEmpty 页面骨架
- index.css 设计令牌文档化，布局令牌与纯色主按钮（去除渐变粉彩）
- 全站路由页接入 PageShell，云账单三 Tab 为标杆
- 主题体系：跟随系统 + 主流/开发者分组，新增 Dracula/Tokyo Night，One Dark 暖灰差异化
- 登录页/侧栏/顶栏去渐变光球，企业克制风
- 修复 AIAlertAnalyzer JSX 与构建依赖导入问题

frontend/src/components/kubernetes/DeploymentDetail.tsx

@@ -123,10 +123,10 @@ export function DeploymentDetail({ clusterCode, namespace, deploymentName, onBac
 
   if (loading) {
     return (
-      <Card className="bg-slate-900 border-slate-800">
+      <Card className="dg-card">
         <CardContent className="p-12 text-center">
-          <Loader2 className="h-6 w-6 animate-spin mx-auto text-slate-500" />
-          <p className="text-slate-500 mt-3">加载中...</p>
+          <Loader2 className="h-6 w-6 animate-spin mx-auto dg-text-muted" />
+          <p className="dg-text-muted mt-3">加载中...</p>
         </CardContent>
       </Card>
     );
@@ -134,10 +134,10 @@ export function DeploymentDetail({ clusterCode, namespace, deploymentName, onBac
 
   if (!deployment) {
     return (
-      <Card className="bg-slate-900 border-slate-800">
+      <Card className="dg-card">
         <CardContent className="p-12 text-center">
-          <XCircle className="h-8 w-8 mx-auto text-red-400" />
-          <p className="text-slate-400 mt-3">未找到 Deployment: {deploymentName}</p>
+          <XCircle className="h-8 w-8 mx-auto dg-text-red" />
+          <p className="dg-text-secondary mt-3">未找到 Deployment: {deploymentName}</p>
           <Button variant="outline" className="mt-4" onClick={onBack}>返回</Button>
         </CardContent>
       </Card>
@@ -173,14 +173,14 @@ export function DeploymentDetail({ clusterCode, namespace, deploymentName, onBac
       />
 
       <Tabs defaultValue="pods">
-        <TabsList className="bg-slate-800 border border-slate-700">
-          <TabsTrigger value="pods" className="data-[state=active]:bg-slate-700">
+        <TabsList className="bg-[var(--dg-bg-tertiary)] border border-[var(--dg-border)]">
+          <TabsTrigger value="pods" className="data-[state=active]:bg-[var(--dg-bg-active)]">
             Pod 列表 ({pods.length})
           </TabsTrigger>
-          <TabsTrigger value="logs" className="data-[state=active]:bg-slate-700">
+          <TabsTrigger value="logs" className="data-[state=active]:bg-[var(--dg-bg-active)]">
             <FileText className="h-4 w-4 mr-1" />日志
           </TabsTrigger>
-          <TabsTrigger value="hpa" className="data-[state=active]:bg-slate-700">
+          <TabsTrigger value="hpa" className="data-[state=active]:bg-[var(--dg-bg-active)]">
             <Gauge className="h-4 w-4 mr-1" />HPA ({hpas.length})
           </TabsTrigger>
         </TabsList>