feat: global shell — header, footer, sidebars, and layout integration

app/(dashboard)/layout.tsx

@@ -1,15 +1,14 @@
+import { DashboardSidebar } from "@/components/dashboard-sidebar"
+import { Header } from "@/components/header"
+
 export default function DashboardLayout({ children }: { children: React.ReactNode }) {
   return (
-    <div className="flex min-h-screen">
-      <aside className="w-64 border-r bg-muted/30 p-4">
-        <h2 className="mb-4 text-lg font-semibold">管理后台</h2>
-        <nav className="space-y-2 text-sm text-muted-foreground">
-          <div>服务管理</div>
-          <div>店铺管理</div>
-          <div>员工管理</div>
-        </nav>
-      </aside>
-      <main className="flex-1 p-6">{children}</main>
+    <div className="flex min-h-screen flex-col">
+      <Header />
+      <div className="flex flex-1">
+        <DashboardSidebar />
+        <main className="flex-1 p-6">{children}</main>
+      </div>
     </div>
   )
 }