feat: add bare-metal deployment configs for Proxmox/LXC

Provide ready-to-use nginx, systemd, and environment configs
for bare-metal installs. Community Proxmox scripts currently
sed-hack the Docker nginx.conf with patterns that don't match,
causing broken pid/log paths and tmpfiles issues on reboot.

deploy/guacd.service

@@ -0,0 +1,12 @@
+[Unit]
+Description=Guacamole Proxy Daemon (guacd)
+After=network.target
+
+[Service]
+Type=simple
+ExecStart=/usr/local/sbin/guacd -f -b 127.0.0.1 -l 4822
+Restart=on-failure
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target