server {
    listen 8080;
    server_name _;
    root /usr/share/nginx/html;
    index index.html;

    location ~ \.mjs$ {
        types { text/javascript mjs; }
        default_type text/javascript;
        try_files $uri =404;
    }

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

    # Backend API — upstream host injected from SPIN_BACKEND_URL (envsubst).
    # local docker-compose: backend:8080 ; cluster: spin-backend.internal.svc.cluster.local:80
    location /api/ {
        proxy_pass http://${SPIN_BACKEND_URL};
        proxy_http_version 1.1;
        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;
        client_max_body_size 50m;
    }
}