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

components/home/RecentPosts.tsx

@@ -44,6 +44,7 @@ export default async function RecentPosts({ locale }: RecentPostsProps) {
                       fill
                       className="w-full h-full object-cover transition-transform duration-700 group-hover:scale-110"
                       sizes="(max-width: 768px) 100vw, 33vw"
+                      loading="lazy"
                     />
                     <div className="absolute inset-0 image-overlay-gradient opacity-0 group-hover:opacity-100 transition-opacity duration-500" />
                     {post.frontmatter.category && (