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/PageTransition.tsx

@@ -0,0 +1,25 @@
+"use client"
+import React, { useEffect, useRef } from "react"
+import { useLocation } from "react-router-dom"
+
+interface PageTransitionProps {
+    children: React.ReactNode
+}
+
+// Simplified page transition - no loading delay for better LCP
+const PageTransition = ({ children }: PageTransitionProps) => {
+    const location = useLocation()
+    const previousPathRef = useRef<string | null>(null)
+
+    useEffect(() => {
+        // Only scroll on path change, not on initial mount
+        if (previousPathRef.current && location.pathname !== previousPathRef.current) {
+            window.scrollTo(0, 0)
+        }
+        previousPathRef.current = location.pathname
+    }, [location.pathname])
+
+    return <>{children}</>
+}
+
+export default PageTransition