feat(admin): rebuild admin panel with full management features

- AdminLayout: sidebar navigation (5 pages)
- Dashboard: real-time service/plugin/uptime stats
- Services: status display for all 4 services
- IoT Management: 8 devices with toggle controls
- Plugins: 11 plugins grid with type badges
- Memory: full CRUD with search, add, delete
- 60 modules, TS zero errors, 256KB JS

frontend/web/src/components/admin/AdminLayout.tsx

@@ -0,0 +1,45 @@
+import { Outlet, NavLink } from 'react-router-dom'
+
+const navItems = [
+  { to: '/admin/dashboard', label: '仪表盘', icon: '◉' },
+  { to: '/admin/services', label: '服务管理', icon: '⚙' },
+  { to: '/admin/iot', label: 'IoT 设备', icon: '⌂' },
+  { to: '/admin/plugins', label: '插件管理', icon: '◇' },
+  { to: '/admin/memory', label: '记忆管理', icon: '♡' },
+]
+
+export default function AdminLayout() {
+  return (
+    <div className="flex h-full">
+      {/* Sidebar */}
+      <nav className="w-52 bg-[#000] border-r border-[#393939] shrink-0 flex flex-col">
+        <div className="p-4 border-b border-[#393939]">
+          <h2 className="text-sm font-semibold text-white/80">管理面板</h2>
+        </div>
+        <div className="flex-1 p-2 space-y-0.5">
+          {navItems.map(item => (
+            <NavLink
+              key={item.to}
+              to={item.to}
+              className={({ isActive }) =>
+                `flex items-center gap-3 px-3 py-2.5 rounded-[14px] text-sm transition-colors ${
+                  isActive
+                    ? 'bg-[#277AF7]/15 text-[#4788FF] font-medium'
+                    : 'text-white/50 hover:text-white/80 hover:bg-white/5'
+                }`
+              }
+            >
+              <span className="text-base">{item.icon}</span>
+              <span>{item.label}</span>
+            </NavLink>
+          ))}
+        </div>
+      </nav>
+
+      {/* Content area */}
+      <div className="flex-1 overflow-auto bg-[#242424]">
+        <Outlet />
+      </div>
+    </div>
+  )
+}