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

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

    # Never let the browser serve a stale SPA shell: it references hashed asset
    # filenames, so a cached index.html strands users on an old build after a
    # deploy (Edge heuristically caches it when no Cache-Control is set). Force
    # revalidation — a cheap 304 when unchanged — so new deploys are picked up.
    location = /index.html {
        add_header Cache-Control "no-cache";
    }

    location ~* \.(js|css|png|jpg|jpeg|gif|ico|svg|woff2)$ {
        expires 1y;
        add_header Cache-Control "public, immutable";
    }
}