fix: SEO canonical URLs, LCP performance, remove unused dependencies

- Remove duplicate app/projects/ route (was causing 5xx and soft 404)
- Fix nginx: redirect www.dk0.dev → dk0.dev (non-www canonical)
- Fix not-found.tsx: locale-prefixed links, remove framer-motion dependency
- Add fetchPriority='high' and will-change to Hero LCP image
- Add preconnect hints for hardcover.app and cms.dk0.dev
- Reduce background blur from 100px to 80px (LCP rendering delay)
- Remove boneyard-js (~20 KiB), replace with custom Skeleton component
- Remove react-icons (~10 KiB), replace with inline SVGs
- Conditionally render mobile menu (saves ~20 DOM nodes)
- Add /books to sitemap
- Optimize image config with explicit deviceSizes/imageSizes

app/not-found.tsx

@@ -1,6 +1,5 @@
 "use client";
 
-import { motion } from "framer-motion";
 import { ArrowLeft, Search } from "lucide-react";
 import Link from "next/link";
 import { useRouter } from "next/navigation";
@@ -21,12 +20,7 @@ export default function NotFound() {
       <div className="max-w-7xl mx-auto w-full">
         <div className="grid grid-cols-1 md:grid-cols-12 gap-4 sm:gap-6 md:gap-8 max-w-5xl mx-auto">
 
-          {/* Main Error Card */}
-          <motion.div
-            initial={{ opacity: 0, y: 30 }}
-            animate={{ opacity: 1, y: 0 }}
-            className="md:col-span-12 bg-white dark:bg-stone-900 rounded-2xl sm:rounded-[2.5rem] md:rounded-[3rem] p-6 sm:p-8 md:p-16 border border-stone-200/60 dark:border-stone-800/60 shadow-sm flex flex-col justify-between min-h-[300px] sm:min-h-[400px]"
-          >
+          <div className="md:col-span-12 bg-white dark:bg-stone-900 rounded-2xl sm:rounded-[2.5rem] md:rounded-[3rem] p-6 sm:p-8 md:p-16 border border-stone-200/60 dark:border-stone-800/60 shadow-sm flex flex-col justify-between min-h-[300px] sm:min-h-[400px]">
             <div>
               <div className="flex items-center gap-3 mb-6 sm:mb-8 md:mb-12">
                 <div className="w-10 h-10 rounded-2xl bg-stone-900 dark:bg-stone-50 flex items-center justify-center text-white dark:text-stone-900 font-black text-xs">
@@ -44,7 +38,7 @@ export default function NotFound() {
 
             <div className="mt-8 sm:mt-10 md:mt-12 flex flex-wrap gap-3 sm:gap-4">
               <Link
-                href="/"
+                href="/en"
                 className="group relative px-6 sm:px-10 py-3 sm:py-4 bg-stone-900 dark:bg-stone-50 text-white dark:text-stone-900 rounded-xl sm:rounded-2xl font-black text-xs uppercase tracking-[0.2em] shadow-xl hover:scale-105 transition-all"
               >
                 Return Home
@@ -56,28 +50,22 @@ export default function NotFound() {
                 Go Back
               </button>
             </div>
-          </motion.div>
+          </div>
 
-          {/* Explore Work Card */}
-          <motion.div
-            initial={{ opacity: 0, x: 20 }}
-            animate={{ opacity: 1, x: 0 }}
-            transition={{ delay: 0.1 }}
-            className="md:col-span-12 bg-stone-900 rounded-2xl sm:rounded-[2.5rem] p-6 sm:p-8 md:p-10 border border-stone-800 shadow-2xl text-white relative overflow-hidden group flex flex-col justify-between min-h-[200px]"
-          >
+          <div className="md:col-span-12 bg-stone-900 rounded-2xl sm:rounded-[2.5rem] p-6 sm:p-8 md:p-10 border border-stone-800 shadow-2xl text-white relative overflow-hidden group flex flex-col justify-between min-h-[200px]">
             <div className="relative z-10">
               <Search className="text-liquid-mint mb-4 sm:mb-6" size={28} />
               <h3 className="text-xl sm:text-2xl font-black uppercase tracking-tighter mb-1 sm:mb-2">Explore Work</h3>
               <p className="text-stone-400 text-sm font-medium">Maybe what you need is in my project archive?</p>
             </div>
             <Link
-              href="/projects"
+              href="/en/projects"
               className="mt-5 sm:mt-8 inline-flex items-center gap-2 text-[10px] font-black uppercase tracking-widest text-liquid-mint group-hover:gap-4 transition-all"
             >
               View Projects <ArrowLeft className="rotate-180" size={14} />
             </Link>
             <div className="absolute top-0 right-0 w-32 h-32 bg-liquid-mint/5 blur-3xl rounded-full -mr-16 -mt-16" />
-          </motion.div>
+          </div>
 
         </div>
       </div>