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]/blog/[slug]/page.tsx

@@ -32,11 +32,6 @@ export async function generateMetadata({ params }: BlogPostProps): Promise<Metad
     description: description,
     alternates: {
       canonical: `${SITE_URL}/${locale}/blog/${slug}`,
-      languages: {
-        de: `${SITE_URL}/de/blog/${slug}`,
-        en: `${SITE_URL}/en/blog/${slug}`,
-        'x-default': `${SITE_URL}/en/blog/${slug}`,
-      },
     },
     openGraph: {
       title: `${post.frontmatter.title} | KLZ Cables`,