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

    # Capture→Review uploads the calibrated lineup PNGs (clean cal + batch) as
    # multipart to /api/v1/slabs/{id}/photos. nginx's default client_max_body_size
    # is 1MB, which 413s on real multi-MB photos. Allow large photo bodies.
    client_max_body_size 25m;

    # Docker embedded DNS for service name resolution (fastapi)
    resolver 127.0.0.11 valid=10s;

    # SPA: fall back to index.html for any path
    # Proxy API calls to the FastAPI backend (M3+)
    # Use variable to defer DNS resolution (docker service name "fastapi")
    location /api/ {
        set $fastapi_upstream fastapi;
        proxy_pass http://$fastapi_upstream:8000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection 'upgrade';
        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;
        proxy_cache_bypass $http_upgrade;
    }

    location / {
        try_files $uri $uri/ /index.html;
    }

    location ~* \.(js|css|png|jpg|jpeg|svg|woff2?)$ {
        expires 7d;
        add_header Cache-Control "public";
        try_files $uri =404;
    }
}