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/GallerySection.tsx

@@ -49,6 +49,7 @@ export default function GallerySection() {
                 fill
                 className="object-cover transition-transform duration-1000 group-hover:scale-110"
                 sizes="(max-width: 768px) 100vw, (max-width: 1200px) 50vw, 33vw"
+                loading="lazy"
               />
               <div className="absolute inset-0 bg-primary-dark/20 group-hover:bg-transparent transition-all duration-500" />
               <div className="absolute inset-0 border-0 group-hover:border-[16px] border-white/10 transition-all duration-500 pointer-events-none" />