Migrate from Vite to Next.js 15 with SSR

- Replace Vite + React Router with Next.js 15 App Router
- Implement i18n with next-intl (URL-based: /de, /en, /sr)
- Add SSR/SSG for all pages (48 static pages generated)
- Setup Supabase SSR client for auth
- Migrate all pages: Home, About, Portfolio, Blog, Contact, Login, Dashboard, Imprint, Privacy, Terms
- Add Docker support with standalone output
- Replace i18next with next-intl JSON translations
- Use next/image for optimized images

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/components-vite/NavLink.tsx

@@ -0,0 +1,32 @@
+// components/NavLink.tsx
+import { Link, useLocation } from 'react-router-dom'
+import React from 'react'
+
+interface NavLinkProps {
+    to: string
+    icon: React.ReactNode
+    label: string
+    onClick?: () => void
+    className?: string
+}
+
+export function NavLink({ to, icon, label, onClick, className }: NavLinkProps) {
+    const location = useLocation()
+    const isActive = location.pathname === to
+
+    return (
+        <Link
+            to={to}
+            onClick={onClick}
+            className={`
+        relative flex items-center gap-2 rounded-full py-2 px-4
+        transition-all duration-200 ease-in-out
+        ${isActive ? 'text-white bg-zinc-700/60' : 'text-zinc-400 hover:text-white hover:bg-zinc-800/30'}
+        ${className}
+      `}
+        >
+            {icon}
+            <span className="text-sm tracking-wide">{label}</span>
+        </Link>
+    )
+}