Replace cron suggestion with systemd timer for kiwix updates

User units in systemd/ with an install.sh that symlinks and enables.
Persistent=true means missed runs (machine off) catch up on next boot.
Logs via journald: journalctl --user -u kiwix-update.service

https://claude.ai/code/session_012gDnantBmFTWZGCiKyjazx

systemd/kiwix-update.service

@@ -0,0 +1,10 @@
+[Unit]
+Description=Kiwix ZIM auto-updater
+After=network-online.target
+Wants=network-online.target
+
+[Service]
+Type=oneshot
+ExecStart=/bin/bash %h/local-ai/kiwix_update.sh
+StandardOutput=journal
+StandardError=journal