feat: Website-Rework mit verbessertem Design, Sicherheit und Deployment

- Neue About/Skills-Sektion hinzugefügt
- Verbesserte UI/UX für alle Komponenten
- Enhanced Contact Form mit Validierung
- Verbesserte Security Headers und Middleware
- Sichere Deployment-Skripte (safe-deploy.sh)
- Zero-Downtime Deployment Support
- Verbesserte Docker-Sicherheit
- Umfassende Sicherheits-Dokumentation
- Performance-Optimierungen
- Accessibility-Verbesserungen

app/api/email/route.tsx

@@ -3,18 +3,47 @@ import nodemailer from "nodemailer";
 import SMTPTransport from "nodemailer/lib/smtp-transport";
 import Mail from "nodemailer/lib/mailer";
 import { PrismaClient } from '@prisma/client';
+import { checkRateLimit, getRateLimitHeaders } from '@/lib/auth';
 
 const prisma = new PrismaClient();
 
+// Sanitize input to prevent XSS
+function sanitizeInput(input: string, maxLength: number = 10000): string {
+    return input
+        .slice(0, maxLength)
+        .replace(/[<>]/g, '') // Remove potential HTML tags
+        .trim();
+}
+
 export async function POST(request: NextRequest) {
     try {
+        // Rate limiting
+        const ip = request.headers.get('x-forwarded-for') || request.headers.get('x-real-ip') || 'unknown';
+        if (!checkRateLimit(ip, 5, 60000)) { // 5 emails per minute per IP
+            return NextResponse.json(
+                { error: 'Zu viele Anfragen. Bitte versuchen Sie es später erneut.' },
+                { 
+                    status: 429,
+                    headers: {
+                        'Content-Type': 'application/json',
+                        ...getRateLimitHeaders(ip, 5, 60000)
+                    }
+                }
+            );
+        }
+
         const body = (await request.json()) as {
             email: string;
             name: string;
             subject: string;
             message: string;
         };
-        const { email, name, subject, message } = body;
+        
+        // Sanitize and validate input
+        const email = sanitizeInput(body.email || '', 255);
+        const name = sanitizeInput(body.name || '', 100);
+        const subject = sanitizeInput(body.subject || '', 200);
+        const message = sanitizeInput(body.message || '', 5000);
 
         console.log('📧 Email request received:', { email, name, subject, messageLength: message.length });
 
@@ -46,6 +75,14 @@ export async function POST(request: NextRequest) {
             );
         }
 
+        // Validate field lengths
+        if (name.length > 100 || subject.length > 200 || message.length > 5000) {
+            return NextResponse.json(
+                { error: "Eingabe zu lang" },
+                { status: 400 },
+            );
+        }
+
         const user = process.env.MY_EMAIL ?? "";
         const pass = process.env.MY_PASSWORD ?? "";