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/Alert.tsx

@@ -0,0 +1,43 @@
+// Alert.tsx
+import React from 'react';
+import { motion } from 'framer-motion';
+import { CheckCircle2, XCircle } from 'lucide-react';
+
+interface AlertProps {
+    variant?: 'success' | 'error';
+    children: React.ReactNode;
+}
+
+export const Alert: React.FC<AlertProps> = ({ variant = 'success', children }) => {
+    const variants = {
+        success: {
+            bg: 'bg-primary/10',
+            border: 'border-primary',
+            text: 'text-primary',
+            icon: <CheckCircle2 className="h-5 w-5" />
+        },
+        error: {
+            bg: 'bg-red-500/10',
+            border: 'border-red-500',
+            text: 'text-red-400',
+            icon: <XCircle className="h-5 w-5" />
+        }
+    };
+
+    const style = variants[variant];
+
+    return (
+        <motion.div
+            initial={{ opacity: 0, y: 10 }}
+            animate={{ opacity: 1, y: 0 }}
+            className={`${style.bg} ${style.border} ${style.text} border rounded-lg p-4 flex items-start space-x-3`}
+        >
+            <span className="flex-shrink-0">{style.icon}</span>
+            <div className="flex-1">{children}</div>
+        </motion.div>
+    );
+};
+
+export const AlertDescription: React.FC<{ children: React.ReactNode }> = ({ children }) => {
+    return <div className="text-sm">{children}</div>;
+};