feat: optimize performance and SEO, integrate Lighthouse CI

- Integrated imgproxy for centralized image optimization
- Implemented Lighthouse CI in Gitea pipeline with native Chromium
- Reached 100/100 SEO score by fixing canonicals, hreflang, and link text
- Optimized LCP by forcing Hero component visibility until hydration
- Decoupled analytics into an async shell to reduce TTI

app/[locale]/layout.tsx

@@ -1,16 +1,16 @@
 import Footer from '@/components/Footer';
 import Header from '@/components/Header';
 import JsonLd from '@/components/JsonLd';
-import AnalyticsProvider from '@/components/analytics/AnalyticsProvider';
-import ScrollDepthTracker from '@/components/analytics/ScrollDepthTracker';
 import SkipLink from '@/components/SkipLink';
 import CMSConnectivityNotice from '@/components/CMSConnectivityNotice';
 import { RecordModeProvider } from '@/components/record-mode/RecordModeContext';
 import { RecordModeVisuals } from '@/components/record-mode/RecordModeVisuals';
 import { ToolCoordinator } from '@/components/record-mode/ToolCoordinator';
+import AnalyticsShell from '@/components/analytics/AnalyticsShell';
 import { Metadata, Viewport } from 'next';
 import { NextIntlClientProvider } from 'next-intl';
 import { getMessages } from 'next-intl/server';
+import dynamic from 'next/dynamic';
 import { Suspense } from 'react';
 import '../../styles/globals.css';
 import { SITE_URL } from '@/lib/schema';
@@ -26,6 +26,13 @@ const inter = Inter({
 
 export const metadata: Metadata = {
   metadataBase: new URL(SITE_URL),
+  alternates: {
+    canonical: '/',
+    languages: {
+      de: '/de',
+      en: '/en',
+    },
+  },
   icons: {
     icon: [
       { url: '/favicon.ico', sizes: 'any' },
@@ -116,10 +123,7 @@ export default async function Layout(props: {
 
             <CMSConnectivityNotice />
 
-            <Suspense fallback={null}>
-              <AnalyticsProvider />
-              <ScrollDepthTracker />
-            </Suspense>
+            <AnalyticsShell />
             <ToolCoordinator feedbackEnabled={feedbackEnabled} />
           </RecordModeProvider>
         </NextIntlClientProvider>