perf: site-wide performance optimizations including image delivery and hero overhaul

app/[locale]/blog/page.tsx

@@ -66,7 +66,8 @@ export default async function BlogIndex({ params }: BlogIndexProps) {
                 alt={featuredPost.frontmatter.title}
                 fill
                 className="absolute inset-0 w-full h-full object-cover scale-105 animate-slow-zoom opacity-40 md:opacity-60"
-                unoptimized
+                sizes="100vw"
+                priority
               />
               <div className="absolute inset-0 image-overlay-gradient" />
             </>
@@ -153,7 +154,7 @@ export default async function BlogIndex({ params }: BlogIndexProps) {
                           alt={post.frontmatter.title}
                           fill
                           className="w-full h-full object-cover transition-transform duration-1000 group-hover:scale-110"
-                          unoptimized
+                          sizes="(max-width: 768px) 100vw, (max-width: 1024px) 50vw, 33vw"
                         />
                         <div className="absolute inset-0 image-overlay-gradient opacity-0 group-hover:opacity-100 transition-opacity duration-500" />
                         {post.frontmatter.category && (