Add Nginx frontend + Backend Docker setup for Coolify deployment

docker-compose.yml

@@ -1,23 +1,24 @@
 services:
   backend:
     build:
-      context: .
-      dockerfile: Dockerfile
+      context: ./backend
+      dockerfile: Dockerfile.backend
     image: wochenplaner-backend:latest
-    container_name: wochenplaner
     restart: unless-stopped
-    
-    # Kein ports: 80/443 - Traefik belegt diese
-    # Port 8000 für API - identischer Host/Container-Port
-    ports:
-      - "8000:8000"
-    
     environment:
       - PORT=8000
-      - JWT_SECRET=${JWT_SECRET:-wochenplaner-jwt-secret-change-me}
-    
+      - JWT_SECRET=${SERVICE_BASE64_64_JWT:-wochenplaner-jwt-secret-change-me}
     volumes:
       - wochenplaner_data:/app/data
+  
+  frontend:
+    image: nginx:alpine
+    restart: unless-stopped
+    ports:
+      - "8000:80"
+    volumes:
+      - ./frontend:/var/www/html:ro
+      - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
 
 volumes:
   wochenplaner_data: