The desktop app joins wss:// sessions (rustls with webpki roots, certificates always checked, clear errors; FIGCRAFT_CA_FILE for private authorities), with one TLS session shared by the reader and writer threads. figcraft-server stops gracefully on SIGTERM/SIGINT/SIGHUP/Ctrl+C, ships in Linux x86_64/aarch64 release archives, and docs/server.md gains a Deploy on a Linux server guide with a hardened systemd unit, Caddyfile, nginx config and Dockerfile in packaging/server.