server {
    listen 80;
    server_name _;
    root /usr/share/nginx/html;
    index index.html;

    # SPA fallback
    location / {
        try_files $uri $uri/ /index.html;
    }

    # API proxy
    location /api/ {
        proxy_pass http://backend:5008;
        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_read_timeout 600s;
        # Stack backups (incl. volume data) can be large in both directions.
        client_max_body_size 0;
        proxy_request_buffering off;
    }

    # WebSocket proxy
    location /ws/ {
        proxy_pass http://backend:5008;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $host;
        proxy_read_timeout 86400s;
    }

    # Basic security headers
    add_header X-Frame-Options "SAMEORIGIN" always;
    add_header X-Content-Type-Options "nosniff" always;
    add_header Referrer-Policy "strict-origin-when-cross-origin" always;
}