fix: stabilize admin dashboard navigation

frontend/src/App.tsx

@@ -19,15 +19,15 @@ function App() {
 
   return (
     <Routes>
-      <Route path="/" element={<Dashboard />} />
       <Route path="/admin" element={<Dashboard />} />
+      <Route path="/" element={<Navigate to="/earth" replace />} />
       <Route path="/earth" element={<Earth />} />
       <Route path="/users" element={<Users />} />
       <Route path="/datasources" element={<DataSources />} />
       <Route path="/data" element={<DataList />} />
       <Route path="/bgp" element={<BGP />} />
       <Route path="/settings" element={<Settings />} />
-      <Route path="*" element={<Navigate to="/" replace />} />
+      <Route path="*" element={<Navigate to="/admin" replace />} />
     </Routes>
   )
 }

frontend/src/components/AppLayout/AppLayout.tsx

@@ -10,7 +10,7 @@ import {
   MenuUnfoldOutlined,
   MenuFoldOutlined,
 } from '@ant-design/icons'
-import { Link, useLocation } from 'react-router-dom'
+import { useLocation, useNavigate } from 'react-router-dom'
 import { useAuthStore } from '../../stores/auth'
 import packageJson from '../../../package.json'
 
@@ -23,18 +23,19 @@ interface AppLayoutProps {
 
 function AppLayout({ children }: AppLayoutProps) {
   const location = useLocation()
+  const navigate = useNavigate()
   const { user, logout } = useAuthStore()
   const [collapsed, setCollapsed] = useState(false)
   const showBanner = true
   const appVersion = `v${packageJson.version}`
 
   const menuItems = [
-    { key: '/', icon: <DashboardOutlined />, label: <Link to="/">仪表盘</Link> },
-    { key: '/datasources', icon: <DatabaseOutlined />, label: <Link to="/datasources">数据源</Link> },
-    { key: '/data', icon: <BarChartOutlined />, label: <Link to="/data">采集数据</Link> },
-    { key: '/bgp', icon: <DeploymentUnitOutlined />, label: <Link to="/bgp">BGP观测</Link> },
-    { key: '/users', icon: <UserOutlined />, label: <Link to="/users">用户管理</Link> },
-    { key: '/settings', icon: <SettingOutlined />, label: <Link to="/settings">系统配置</Link> },
+    { key: '/admin', icon: <DashboardOutlined />, label: '仪表盘' },
+    { key: '/datasources', icon: <DatabaseOutlined />, label: '数据源' },
+    { key: '/data', icon: <BarChartOutlined />, label: '采集数据' },
+    { key: '/bgp', icon: <DeploymentUnitOutlined />, label: 'BGP观测' },
+    { key: '/users', icon: <UserOutlined />, label: '用户管理' },
+    { key: '/settings', icon: <SettingOutlined />, label: '系统配置' },
   ]
 
   return (
@@ -68,6 +69,11 @@ function AppLayout({ children }: AppLayoutProps) {
               mode="inline"
               selectedKeys={[location.pathname]}
               items={menuItems}
+              onClick={({ key }) => {
+                if (key !== location.pathname) {
+                  navigate(key)
+                }
+              }}
             />
           </div>
 

frontend/src/pages/Dashboard/Dashboard.tsx

@@ -90,6 +90,8 @@ const RESTART_GUIDE_LINES: Record<RestartAction, string[]> = {
   ],
 }
 
+let cachedDashboardStats: Stats | null = null
+
 function getRestartConfirmMessage(action: RestartAction): string {
   if (action === 'restart-database') {
     return '将重启 PostgreSQL 和 Redis，页面通常保持在线，但相关请求可能短暂波动。'
@@ -102,8 +104,8 @@ function getRestartConfirmMessage(action: RestartAction): string {
 
 function Dashboard() {
   const { token, clearAuth, user } = useAuthStore()
-  const [stats, setStats] = useState<Stats | null>(null)
-  const [loading, setLoading] = useState(true)
+  const [stats, setStats] = useState<Stats | null>(cachedDashboardStats)
+  const [loading, setLoading] = useState(cachedDashboardStats === null)
   const [wsConnected, setWsConnected] = useState(false)
   const [error, setError] = useState<string | null>(null)
   const [restartModalOpen, setRestartModalOpen] = useState(false)
@@ -122,7 +124,9 @@ function Dashboard() {
 
     const fetchStats = async () => {
       try {
-        setLoading(true)
+        if (!cachedDashboardStats) {
+          setLoading(true)
+        }
         const res = await fetch('/api/v1/dashboard/stats', {
           headers: { Authorization: `Bearer ${token}` },
         })
@@ -132,6 +136,7 @@ function Dashboard() {
           return
         }
         const data = await res.json()
+        cachedDashboardStats = data
         setStats(data)
         setError(null)
       } catch (err) {
@@ -164,7 +169,9 @@ function Dashboard() {
           try {
             const msg = JSON.parse(event.data)
             if (msg.type === 'data_frame' && msg.channel === 'dashboard') {
-              setStats(msg.payload?.stats as Stats)
+              const nextStats = msg.payload?.stats as Stats
+              cachedDashboardStats = nextStats
+              setStats(nextStats)
             }
           } catch (e) {
             console.error('Parse WS message error:', e)