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

    # Tinode webapp uses real (History API) client-side routing, so any unknown path
    # can safely fall back to index.html -- the app resolves the actual view/topic
    # client-side from the path itself once index.html loads.
    location / {
        try_files $uri $uri/ /index.html;
    }

    # Filenames here aren't content-hashed, so a long/immutable cache would keep
    # serving a stale bundle after every deploy. Force revalidation instead:
    # cheap 304s when unchanged, immediate pickup of new content when not.
    location /umd/ {
        add_header Cache-Control "no-cache";
    }

    location /img/ {
        add_header Cache-Control "public, max-age=86400";
    }
}