feat(ext): enhance error handling and improve UI structure

packages/extension/src/entrypoints/background.ts

@@ -145,6 +145,10 @@ function registerCommandHandlers(): void {
 		// Execute task (don't await - runs in background)
 		agent.execute(task).catch((error) => {
 			console.error('[PageAgentExt] Task execution error:', error)
+			const message = error instanceof Error ? error.message : String(error)
+			// Broadcast error as a history event so it persists in UI
+			const errorEvent: HistoricalEvent = { type: 'error', message }
+			eventBroadcaster.history([errorEvent])
 			eventBroadcaster.status('error')
 		})
 	})

packages/extension/src/entrypoints/sidepanel/App.tsx

@@ -109,7 +109,7 @@ export default function App() {
 	return (
 		<div className="flex flex-col h-screen bg-background">
 			{/* Header */}
-			<div className="flex items-center justify-between border-b px-3 py-2">
+			<header className="flex items-center justify-between border-b px-3 py-2">
 				<div className="flex items-center gap-2">
 					<Logo className="size-5" />
 					<span className="text-sm font-medium">Page Agent Ext</span>
@@ -120,10 +120,10 @@ export default function App() {
 						<Settings className="size-3.5" />
 					</Button>
 				</div>
-			</div>
+			</header>
 
 			{/* Content */}
-			<div className="flex-1 overflow-hidden flex flex-col">
+			<main className="flex-1 overflow-hidden flex flex-col">
 				{/* Current task */}
 				{currentTask && (
 					<div className="border-b px-3 py-2 bg-muted/30">
@@ -145,10 +145,10 @@ export default function App() {
 					{/* Activity indicator at bottom */}
 					{activity && <ActivityCard activity={activity} />}
 				</div>
-			</div>
+			</main>
 
 			{/* Input */}
-			<div className="border-t p-3">
+			<footer className="border-t p-3">
 				<InputGroup className="relative rounded-lg">
 					<InputGroupTextarea
 						ref={textareaRef}
@@ -183,7 +183,7 @@ export default function App() {
 						)}
 					</InputGroupAddon>
 				</InputGroup>
-			</div>
+			</footer>
 		</div>
 	)
 }

packages/extension/src/entrypoints/sidepanel/components/ErrorBoundary.tsx

@@ -0,0 +1,49 @@
+import { AlertTriangle, RotateCcw } from 'lucide-react'
+import { Component, type ErrorInfo, type ReactNode } from 'react'
+
+import { Button } from '@/components/ui/button'
+
+interface Props {
+	children: ReactNode
+}
+
+interface State {
+	hasError: boolean
+	error: Error | null
+}
+
+export class ErrorBoundary extends Component<Props, State> {
+	state: State = { hasError: false, error: null }
+
+	static getDerivedStateFromError(error: Error): State {
+		return { hasError: true, error }
+	}
+
+	componentDidCatch(error: Error, errorInfo: ErrorInfo) {
+		console.error('[ErrorBoundary]', error, errorInfo.componentStack)
+	}
+
+	handleReload = () => {
+		window.location.reload()
+	}
+
+	render() {
+		if (!this.state.hasError) {
+			return this.props.children
+		}
+
+		return (
+			<div className="flex flex-col items-center justify-center h-screen bg-background p-6 text-center">
+				<AlertTriangle className="size-12 text-destructive mb-4" />
+				<h2 className="text-lg font-semibold mb-2">Something went wrong</h2>
+				<p className="text-sm text-muted-foreground mb-4 max-w-xs">
+					{this.state.error?.message || 'An unexpected error occurred'}
+				</p>
+				<Button variant="outline" size="sm" onClick={this.handleReload}>
+					<RotateCcw className="size-3.5 mr-2" />
+					Reload Panel
+				</Button>
+			</div>
+		)
+	}
+}

packages/extension/src/entrypoints/sidepanel/components/cards/index.tsx

@@ -60,11 +60,11 @@ function ReflectionItem({ icon, value }: { icon: string; value: string }) {
 
 	return (
 		<Fragment>
-			<span className="text-xs">{icon}</span>
+			<span className="text-xs flex justify-center">{icon}</span>
 			<span
 				className={cn(
 					'text-[11px] text-muted-foreground cursor-pointer hover:text-muted-foreground/70',
-					!expanded && 'line-clamp-2'
+					!expanded && 'line-clamp-1'
 				)}
 				onClick={() => setExpanded(!expanded)}
 			>
@@ -93,11 +93,11 @@ function ReflectionSection({
 	if (items.length === 0) return null
 
 	return (
-		<div className="mb-3">
-			<div className="text-[11px] font-semibold text-foreground uppercase tracking-wide mb-2">
+		<div className="mb-2">
+			{/* <div className="text-[11px] font-semibold text-foreground uppercase tracking-wide mb-2">
 				Reflection
-			</div>
-			<div className="grid grid-cols-[auto_1fr] gap-x-2 gap-y-2">
+			</div> */}
+			<div className="grid grid-cols-[14px_1fr] gap-x-2 gap-y-2">
 				{items.map((item) => (
 					<ReflectionItem key={item.label} icon={item.icon} value={item.value!} />
 				))}
@@ -162,15 +162,17 @@ export function EventCard({ event }: { event: HistoricalEvent }) {
 
 	if (event.type === 'step') {
 		return (
-			<div className="rounded-lg border bg-card p-2.5">
+			<div className="rounded-lg border-l-2 border-l-blue-500/50 border bg-muted/40 p-2.5">
+				<div className="text-[11px] font-semibold text-foreground tracking-wide mb-2">Step</div>
+
 				{/* Reflection */}
 				{event.reflection && <ReflectionSection reflection={event.reflection} />}
 
 				{/* Action */}
 				{event.action && (
 					<div>
-						<div className="text-[11px] font-semibold text-foreground uppercase tracking-wide mb-2">
-							Action
+						<div className="text-[11px] font-semibold text-foreground tracking-wide mb-1">
+							Actions
 						</div>
 						<div className="flex items-start gap-2">
 							<ActionIcon
@@ -179,7 +181,7 @@ export function EventCard({ event }: { event: HistoricalEvent }) {
 							/>
 							<div className="flex-1 min-w-0">
 								<p className="text-xs text-foreground/80 mb-0.5">
-									<span className="font-medium">{event.action.name}</span>
+									<span className="font-medium text-foreground/70">{event.action.name}</span>
 									<span className="text-muted-foreground/70 ml-1.5">
 										{JSON.stringify(event.action.input)}
 									</span>
@@ -198,10 +200,10 @@ export function EventCard({ event }: { event: HistoricalEvent }) {
 
 	if (event.type === 'observation') {
 		return (
-			<div className="rounded-lg border bg-card p-2.5">
-				<div className="text-[11px] font-semibold text-foreground uppercase tracking-wide mb-2">
+			<div className="rounded-lg border-l-2 border-l-green-500/50 border bg-muted/40 p-2.5">
+				{/* <div className="text-[11px] font-semibold text-foreground uppercase tracking-wide mb-2">
 					Observation
-				</div>
+				</div> */}
 				<div className="flex items-start gap-2">
 					<Eye className="size-3.5 text-green-500 shrink-0 mt-0.5" />
 					<span className="text-[11px] text-muted-foreground">{event.content}</span>
@@ -248,7 +250,7 @@ export function ActivityCard({ activity }: { activity: AgentActivity }) {
 	const info = getActivityInfo()
 
 	return (
-		<div className="flex items-center gap-2 rounded-lg border bg-card/50 p-2.5 animate-pulse">
+		<div className="flex items-center gap-2 rounded-lg border bg-muted/40 p-2.5 animate-pulse">
 			<div className="relative">
 				<Sparkles className={cn('size-3.5', info.color)} />
 				<span

packages/extension/src/entrypoints/sidepanel/main.tsx

@@ -2,11 +2,14 @@ import React from 'react'
 import ReactDOM from 'react-dom/client'
 
 import App from './App'
+import { ErrorBoundary } from './components/ErrorBoundary'
 
 import '@/assets/index.css'
 
 ReactDOM.createRoot(document.getElementById('root')!).render(
 	<React.StrictMode>
-		<App />
+		<ErrorBoundary>
+			<App />
+		</ErrorBoundary>
 	</React.StrictMode>
 )