chore: vapor playground preview script

playground/package.json

@@ -5,7 +5,8 @@
   "scripts": {
     "dev": "node ./setup/vite.js",
     "build": "vite build -c vite.prod.config.ts",
-    "preview": "vite preview -c vite.prod.config.ts"
+    "prepreview": "cd ../ && pnpm run build runtime-vapor -f esm-bundler",
+    "preview": "pnpm run build && vite preview -c vite.prod.config.ts"
   },
   "dependencies": {
     "@vueuse/core": "^11.1.0",