Deploy to a DigitalOcean droplet: wizwar is on the internet

Production shape: one Node process serves the built client and the
websocket on a single port (SPA fallback, same-origin wss in the
client), with Caddy terminating auto-TLS in front. The droplet
(nyc3, $6/mo) runs it under systemd as an unprivileged user with room
files on the persistent disk at /var/lib/wizwar/rooms — deploys and
reboots cannot eat a game. deploy/ carries the one-time droplet setup
script, the systemd unit, the Caddyfile, an everyday deploy script
(build locally, rsync, install, restart), and a README. Live at
https://wizwar.104.236.96.198.sslip.io via sslip.io, so TLS needed no
DNS setup at all. Verified over the real internet: room created,
second player joined, expansion game started, hands dealt, room file
persisted. Fixed en route: rsync's unanchored "data" exclude was
stripping the engine's card database, and tsx must ship (it is the
runtime).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

deploy/Caddyfile

@@ -0,0 +1,6 @@
+# Caddy terminates TLS (automatic certificates) and proxies to the game.
+# Replace the hostname with your domain, or use the sslip.io form
+# (wizwar.<droplet-ip>.sslip.io) for zero DNS setup.
+{$WIZWAR_HOST}
+
+reverse_proxy localhost:8787