feat: downgrade tech stack to stable versions and integrate GA4 error monitoring

- Downgrade Next.js 16→14.2, React 19→18.3, Tailwind 4→3.4
- Add comprehensive GA4 error monitoring system
- Create Jenkins CI/CD pipeline with quality gates
- Fix build issues: ESLint, SWC conflict, config format
- Add documentation for deployment and error tracking

src/app/layout.tsx

@@ -5,6 +5,7 @@ import "./globals.css";
 import { Suspense } from "react";
 import { ThemeProvider } from "@/contexts/theme-context";
 import { GoogleAnalyticsWrapper } from "@/components/analytics/GoogleAnalyticsWrapper";
+import { GlobalErrorTracker } from "@/components/analytics/GlobalErrorTracker";
 import { CookieConsent } from "@/components/analytics/CookieConsent";
 import { PerformanceTracker } from "@/components/analytics/PerformanceTracker";
 import { OutboundLinkTracker } from "@/components/analytics/OutboundLinkTracker";
@@ -151,6 +152,7 @@ export default function RootLayout({
         </a>
         <ScrollProgress />
         <GoogleAnalyticsWrapper />
+        <GlobalErrorTracker />
         <PerformanceTracker />
         <OutboundLinkTracker />
         <ScrollDepthTracker />