feat(WEB): 에러 리포팅 시스템 및 ErrorBoundary 개선

- 에러 리포팅 유틸리티 및 API route 추가
- ErrorBoundary(error.tsx) 에러 리포팅 연동
- providers 컴포넌트 구조 추가
- layout에 provider 적용

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/providers/ChunkErrorHandler.tsx

@@ -0,0 +1,68 @@
+'use client';
+
+import { useEffect } from 'react';
+import { reportErrorToSlack } from '@/lib/error-reporting';
+
+/**
+ * ChunkLoadError 전역 감지 컴포넌트
+ *
+ * 배포 후 캐시된 구버전 JS 청크 로딩 실패를 감지하여 Slack으로 전송
+ * - window 'error' 이벤트: <script> 태그 로딩 실패
+ * - window 'unhandledrejection': dynamic import() 실패
+ */
+
+const CHUNK_ERROR_PATTERNS = [
+  'Loading chunk',
+  'ChunkLoadError',
+  'Failed to fetch dynamically imported module',
+  'error loading dynamically imported module',
+];
+
+function isChunkError(message: string): boolean {
+  return CHUNK_ERROR_PATTERNS.some((pattern) =>
+    message.toLowerCase().includes(pattern.toLowerCase())
+  );
+}
+
+function sendReport(message: string, stack?: string) {
+  reportErrorToSlack({
+    errorType: 'CHUNK_LOAD_ERROR',
+    message,
+    pageUrl: window.location.href,
+    timestamp: new Date().toISOString(),
+    stack: stack?.slice(0, 500),
+    userAgent: navigator.userAgent,
+  });
+}
+
+export function ChunkErrorHandler() {
+  useEffect(() => {
+    function handleError(event: ErrorEvent) {
+      if (event.message && isChunkError(event.message)) {
+        sendReport(event.message, event.error?.stack);
+      }
+    }
+
+    function handleRejection(event: PromiseRejectionEvent) {
+      const reason = event.reason;
+      const message =
+        reason instanceof Error ? reason.message : String(reason ?? '');
+      if (isChunkError(message)) {
+        sendReport(
+          message,
+          reason instanceof Error ? reason.stack?.slice(0, 500) : undefined
+        );
+      }
+    }
+
+    window.addEventListener('error', handleError);
+    window.addEventListener('unhandledrejection', handleRejection);
+
+    return () => {
+      window.removeEventListener('error', handleError);
+      window.removeEventListener('unhandledrejection', handleRejection);
+    };
+  }, []);
+
+  return null;
+}