chore: better UMD local dev serving

packages/page-agent/package.json

@@ -37,10 +37,9 @@
 	},
 	"homepage": "https://alibaba.github.io/page-agent/",
 	"scripts": {
-		"build": "npm run build:lib && npm run build:umd",
-		"build:lib": "MODE=lib vite build",
-		"build:umd": "MODE=umd vite build",
-		"build:watch": "MODE=umd vite build --watch",
+		"build": "MODE=lib vite build && MODE=umd vite build",
+		"serve": "npx serve dist/umd -p 5173",
+		"dev:umd": "concurrently \"MODE=umd vite build --watch\" \"npm run serve\"",
 		"prepublishOnly": "node -e \"const fs=require('fs');['README.md','LICENSE'].forEach(f=>fs.copyFileSync('../../'+f,f))\"",
 		"postpublish": "node -e \"['README.md','LICENSE'].forEach(f=>{try{require('fs').unlinkSync(f)}catch{}})\""
 	},