fix: add ErrorBoundary to isolate client-side rendering errors

src/app/page.tsx

@@ -8,6 +8,7 @@ import TimeSeriesChart from '@/components/charts/TimeSeriesChart';
 import NetworkChart from '@/components/charts/NetworkChart';
 import NodeTable from '@/components/report/NodeTable';
 import AlertSection from '@/components/report/AlertSection';
+import ErrorBoundary from '@/components/ErrorBoundary';
 
 export default function Home() {
   const [days, setDays] = useState(7);
@@ -51,7 +52,7 @@ export default function Home() {
   if (error || !data) {
     return (
       <div className="min-h-screen flex items-center justify-center">
-        <div className="text-red-500">데이터 로딩 실패: {error?.message}</div>
+        <div className="text-red-500">데이터 로딩 실패: {String(error)}</div>
       </div>
     );
   }
@@ -59,11 +60,13 @@ export default function Home() {
   return (
     <main className="min-h-screen bg-gray-100 p-6">
       <div ref={reportRef} className="max-w-7xl mx-auto space-y-6">
+        <ErrorBoundary fallback="ReportHeader 오류">
           <ReportHeader
             start={data.period.start}
             end={data.period.end}
             onExportPdf={handleExportPdf}
           />
+        </ErrorBoundary>
 
         <div className="flex gap-2">
           {[1, 3, 7, 14, 30].map((d) => (
@@ -79,23 +82,36 @@ export default function Home() {
           ))}
         </div>
 
+        <ErrorBoundary fallback="SummaryCards 오류">
           <SummaryCards
             cpu={data.metrics.cpu}
             memory={data.metrics.memory}
             disk={data.metrics.disk}
             network={data.metrics.network}
           />
+        </ErrorBoundary>
 
+        <ErrorBoundary fallback="CPU 차트 오류">
           <TimeSeriesChart title="CPU 사용률" instances={data.metrics.cpu} unit="%" />
+        </ErrorBoundary>
+        <ErrorBoundary fallback="Memory 차트 오류">
           <TimeSeriesChart title="Memory 사용률" instances={data.metrics.memory} unit="%" />
+        </ErrorBoundary>
+        <ErrorBoundary fallback="Disk 차트 오류">
           <TimeSeriesChart title="Disk 사용률" instances={data.metrics.disk} unit="%" />
+        </ErrorBoundary>
 
-        {data.metrics.nas.length > 0 && (
+        {data.metrics.nas && data.metrics.nas.length > 0 && (
+          <ErrorBoundary fallback="NAS 차트 오류">
             <TimeSeriesChart title="NAS 사용률" instances={data.metrics.nas} unit="%" />
+          </ErrorBoundary>
         )}
 
+        <ErrorBoundary fallback="Network 차트 오류">
           <NetworkChart data={data.metrics.network} />
+        </ErrorBoundary>
 
+        <ErrorBoundary fallback="NodeTable 오류">
           <div>
             <h2 className="text-lg font-semibold text-gray-800 mb-3">노드별 상세</h2>
             <NodeTable
@@ -105,7 +121,9 @@ export default function Home() {
               disk={data.metrics.disk}
             />
           </div>
+        </ErrorBoundary>
 
+        <ErrorBoundary fallback="AlertSection 오류">
           <div>
             <h2 className="text-lg font-semibold text-gray-800 mb-3">주의 구간</h2>
             <AlertSection
@@ -114,6 +132,7 @@ export default function Home() {
               disk={data.metrics.disk}
             />
           </div>
+        </ErrorBoundary>
       </div>
     </main>
   );

src/components/ErrorBoundary.tsx

@@ -0,0 +1,37 @@
+'use client';
+
+import { Component, ReactNode } from 'react';
+
+interface Props {
+  children: ReactNode;
+  fallback?: string;
+}
+
+interface State {
+  hasError: boolean;
+  error: Error | null;
+}
+
+export default class ErrorBoundary extends Component<Props, State> {
+  constructor(props: Props) {
+    super(props);
+    this.state = { hasError: false, error: null };
+  }
+
+  static getDerivedStateFromError(error: Error): State {
+    return { hasError: true, error };
+  }
+
+  render() {
+    if (this.state.hasError) {
+      return (
+        <div className="bg-red-50 border border-red-200 rounded-lg p-4">
+          <p className="text-red-800 text-sm font-medium">{this.props.fallback || '컴포넌트 렌더링 오류'}</p>
+          <p className="text-red-600 text-xs mt-1">{this.state.error?.message}</p>
+          <pre className="text-red-500 text-xs mt-2 overflow-auto max-h-40">{this.state.error?.stack}</pre>
+        </div>
+      );
+    }
+    return this.props.children;
+  }
+}

src/components/charts/NetworkChart.tsx

@@ -4,7 +4,7 @@ import dynamic from 'next/dynamic';
 import type { NetworkMetrics } from '@/types/metrics';
 import { formatTimestamp, formatBytes } from '@/lib/formatters';
 
-const ReactECharts = dynamic(() => import('echarts-for-react'), { ssr: false });
+const ReactECharts = dynamic(() => import('echarts-for-react').then(mod => mod), { ssr: false, loading: () => <div style={{height: 300}} /> });
 
 interface NetworkChartProps {
   data: NetworkMetrics;

src/components/charts/TimeSeriesChart.tsx

@@ -4,7 +4,7 @@ import dynamic from 'next/dynamic';
 import type { MetricInstance } from '@/types/metrics';
 import { formatTimestamp } from '@/lib/formatters';
 
-const ReactECharts = dynamic(() => import('echarts-for-react'), { ssr: false });
+const ReactECharts = dynamic(() => import('echarts-for-react').then(mod => mod), { ssr: false, loading: () => <div style={{height: 300}} /> });
 
 interface TimeSeriesChartProps {
   title: string;