refactor: zod tree-shaking; better error handling in agent steps

packages/website/src/pages/docs/features/custom-tools/page.tsx

@@ -25,7 +25,7 @@ export default function CustomTools() {
 					</p>
 
 					<CodeEditor
-						code={`import zod from 'zod'
+						code={`import * as zod from 'zod'
 import { PageAgent, tool } from 'page-agent'
 
 // override internal tool

packages/website/src/pages/docs/introduction/troubleshooting/page.tsx

@@ -362,11 +362,6 @@ export default function TroubleshootingPage() {
 			{/* Header */}
 			<div className="mb-10">
 				<h1 className="text-4xl font-bold mb-4 text-gray-900 dark:text-white">Troubleshooting</h1>
-				{/* <p className="text-lg text-gray-600 dark:text-gray-300">
-					{isZh
-						? '遇到问题了？按症状查找解决方案。'
-						: 'Running into issues? Find solutions by symptom.'}
-				</p> */}
 			</div>
 
 			{/* Two-column: content + TOC */}