add systemd user unit so the dev server starts at boot

deploy/dvorakmortonxd-dev.service

@@ -0,0 +1,44 @@
+# User systemd service for the dvorakmortonxd.dev dev server.
+#
+# Install (no root needed, runs as the current user):
+#
+#   mkdir -p ~/.config/systemd/user
+#   cp deploy/dvorakmortonxd-dev.service ~/.config/systemd/user/
+#   systemctl --user daemon-reload
+#   systemctl --user enable --now dvorakmortonxd-dev.service
+#   loginctl enable-linger "$USER"   # once: start at boot without logging in
+#
+# Manage:
+#   systemctl --user status  dvorakmortonxd-dev
+#   systemctl --user restart dvorakmortonxd-dev
+#   systemctl --user stop    dvorakmortonxd-dev
+#   journalctl --user -u dvorakmortonxd-dev -f
+#
+# It shares .next/dev/lock with a manual `npm run dev`, so stop the service
+# before starting one by hand.
+
+[Unit]
+Description=dvorakmortonxd.dev dev server (custom Next.js dev wrapper)
+Documentation=file:///home/martin/dvorakmortonxd.dev/README.md
+After=network.target
+
+[Service]
+Type=simple
+WorkingDirectory=/home/martin/dvorakmortonxd.dev
+# Bind all interfaces so the Cloudflare tunnel host can reach :3000. Pin
+# HOSTNAME explicitly: the dev server reads process.env.HOSTNAME and would
+# otherwise try to bind to whatever systemd/the shell exported.
+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=default.target