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/App.tsx

@@ -2,7 +2,12 @@ import { Routes, Route, Navigate } from 'react-router-dom'
 import { useAuthStore } from './store/authStore'
 import AppLayout from './components/layout/AppLayout'
 import ChatPage from './pages/chat/ChatPage'
+import AdminLayout from './components/admin/AdminLayout'
 import DashboardPage from './pages/admin/DashboardPage'
+import ServicesPage from './pages/admin/ServicesPage'
+import IoTManagementPage from './pages/admin/IoTManagementPage'
+import PluginsPage from './pages/admin/PluginsPage'
+import MemoryPage from './pages/admin/MemoryPage'
 import LoginPage from './pages/LoginPage'
 
 export default function App() {
@@ -23,8 +28,14 @@ export default function App() {
         <Route path="/" element={<Navigate to="/chat" replace />} />
         <Route path="/chat" element={<ChatPage />} />
         <Route path="/chat/:sessionId" element={<ChatPage />} />
-        <Route path="/admin/dashboard" element={<DashboardPage />} />
-        <Route path="*" element={<Navigate to="/chat" replace />} />
+        <Route path="/admin" element={<AdminLayout />}>
+          <Route index element={<Navigate to="/admin/dashboard" replace />} />
+          <Route path="dashboard" element={<DashboardPage />} />
+          <Route path="services" element={<ServicesPage />} />
+          <Route path="iot" element={<IoTManagementPage />} />
+          <Route path="plugins" element={<PluginsPage />} />
+          <Route path="memory" element={<MemoryPage />} />
+        </Route>
       </Routes>
     </AppLayout>
   )