chore: add systemd service for auto-update on LXC boot

Runs boot-update.sh before PM2 starts to ensure the app is
always up-to-date with main branch after container reboot.

v1.22.0

scripts/my-weekly-todo-update.service

@@ -0,0 +1,18 @@
+[Unit]
+Description=My Weekly ToDo List - Boot Update (git pull + build)
+After=network-online.target
+Wants=network-online.target
+Before=pm2-root.service
+
+[Service]
+Type=oneshot
+ExecStart=/bin/bash /root/My-Weekly-ToDo-List/scripts/boot-update.sh
+WorkingDirectory=/root/My-Weekly-ToDo-List
+Environment=HOME=/root
+Environment=PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+StandardOutput=journal+console
+StandardError=journal+console
+TimeoutStartSec=300
+
+[Install]
+WantedBy=multi-user.target