5. Trỏ Tên Miền DNS Cloudflare, Proxy Ẩn IP & Cấu Hình Nginx Reverse Proxy

# /etc/nginx/sites-available/app.conf
server {
    listen 80;
    server_name app.tencongty.com;

    location / {
        proxy_pass http://127.0.0.1:5678; # Trỏ vào container n8n hoặc Web App
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        
        # Hỗ trợ WebSocket cho Realtime App
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
}