feat: setup wizard page for first-deploy initialization

- SetupWizardPage: step-by-step config (DB, admin, project)
- Connects directly to AbstractWizard via SSH tunnel (127.0.0.1)
- App.tsx: detect backend health, show wizard if not ready
- Auto-switch wizard to readonly after setup
- Add VITE_WIZARD_PORT build arg
- Add vite-env.d.ts for type safety

src/App.tsx

@@ -1,7 +1,9 @@
+import { useState, useEffect } from 'react'
 import { BrowserRouter, Routes, Route, Navigate } from 'react-router-dom'
 import { useAuth } from '@/hooks/useAuth'
 import Sidebar from '@/components/Sidebar'
 import LoginPage from '@/pages/LoginPage'
+import SetupWizardPage from '@/pages/SetupWizardPage'
 import DashboardPage from '@/pages/DashboardPage'
 import IssuesPage from '@/pages/IssuesPage'
 import IssueDetailPage from '@/pages/IssueDetailPage'
@@ -11,12 +13,41 @@ import ProjectDetailPage from '@/pages/ProjectDetailPage'
 import MilestonesPage from '@/pages/MilestonesPage'
 import MilestoneDetailPage from '@/pages/MilestoneDetailPage'
 import NotificationsPage from '@/pages/NotificationsPage'
+import api from '@/services/api'
+
+const WIZARD_PORT = Number(import.meta.env.VITE_WIZARD_PORT) || 18080
+
+type AppState = 'checking' | 'setup' | 'ready'
 
 export default function App() {
+  const [appState, setAppState] = useState<AppState>('checking')
   const { user, loading, login, logout } = useAuth()
 
+  const checkBackend = async () => {
+    try {
+      await api.get('/health')
+      setAppState('ready')
+    } catch {
+      setAppState('setup')
+    }
+  }
+
+  useEffect(() => { checkBackend() }, [])
+
+  // Checking backend availability
+  if (appState === 'checking') {
+    return <div className="loading">检查后端状态...</div>
+  }
+
+  // Backend not ready — show setup wizard
+  if (appState === 'setup') {
+    return <SetupWizardPage wizardPort={WIZARD_PORT} onComplete={checkBackend} />
+  }
+
+  // Backend ready but auth loading
   if (loading) return <div className="loading">加载中...</div>
 
+  // Not logged in
   if (!user) {
     return (
       <BrowserRouter>