feat(01-01): React + Vite + Tailwind v4 SPA scaffold con API client

- Vite react-ts project con base: '/postgenerator/' (Pitfall #9 risolto)
- Tailwind v4 via @tailwindcss/vite plugin + @import "tailwindcss" in index.css
- react-router-dom con BrowserRouter basename="/postgenerator"
- @tanstack/react-query con QueryClientProvider
- lucide-react installato per icone
- src/api/client.ts: API_BASE='/postgenerator/api', apiFetch<T> con error handling
- Dev proxy: /postgenerator/api -> http://localhost:8000 (strip /postgenerator)
- App.tsx: HomePage placeholder "Setup completo", struttura Routes pronta
- Build Vite: 253.90kB JS + 5.53kB CSS, nessun errore TypeScript

frontend/vite.config.ts

@@ -0,0 +1,23 @@
+import { defineConfig } from 'vite'
+import react from '@vitejs/plugin-react'
+import tailwindcss from '@tailwindcss/vite'
+
+// https://vite.dev/config/
+export default defineConfig({
+  plugins: [react(), tailwindcss()],
+
+  // CRITICAL: base path must match the nginx subpath and FastAPI root_path
+  base: '/postgenerator/',
+
+  server: {
+    proxy: {
+      // In dev, proxy /postgenerator/api -> localhost:8000/api
+      // rewrite strips the /postgenerator prefix so FastAPI sees /api/...
+      '/postgenerator/api': {
+        target: 'http://localhost:8000',
+        changeOrigin: true,
+        rewrite: (path) => path.replace('/postgenerator', ''),
+      },
+    },
+  },
+})