run the dev server as a system-wide systemd unit (boots without login/linger)

deploy/dvorakmortonxd-dev.system.service

@@ -0,0 +1,31 @@
+[Unit]
+Description=dvorakmortonxd.dev dev server (custom Next.js dev wrapper)
+Documentation=file:///home/martin/dvorakmortonxd.dev/README.md
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=simple
+User=martin
+Group=martin
+WorkingDirectory=/home/martin/dvorakmortonxd.dev
+# A system service does not inherit a login environment, so set HOME/PATH
+# explicitly (Next.js wants a writable HOME for its cache).
+Environment=HOME=/home/martin
+Environment=PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+# Bind all interfaces so the Cloudflare tunnel host can reach :3000. The dev
+# server reads process.env.HOSTNAME, so pin it rather than inheriting it.
+Environment=HOSTNAME=0.0.0.0
+Environment=PORT=3000
+# A reboot can leave a stale dev lock behind; clear it before starting.
+ExecStartPre=/bin/rm -f /home/martin/dvorakmortonxd.dev/.next/dev/lock
+ExecStart=/bin/node /home/martin/dvorakmortonxd.dev/scripts/dev-server.mjs
+Restart=always
+RestartSec=3
+# Give Next.js a moment to shut down cleanly.
+TimeoutStopSec=15
+StandardOutput=journal
+StandardError=journal
+
+[Install]
+WantedBy=multi-user.target