Fix: Nginx Upstream Timeout (504 Gateway Timeout)

Nginx's default proxy timeout is 60 seconds. Applications that take longer — AI inference, large file processing, database-heavy requests — hit this limit and return 504.

location / {
    proxy_pass http://127.0.0.1:3000;

    proxy_connect_timeout  60s;
    proxy_send_timeout    300s;   # Time to send request to upstream
    proxy_read_timeout    300s;   # Time to read response from upstream
    send_timeout          300s;
}

Set timeouts in the specific location block rather than globally — this avoids applying long timeouts to fast endpoints.

nginx -t && systemctl reload nginx