Shit, looks like these might be needed in order to run the stupid web gui. :-(

Near as I can tell, I do not need these services, and it is nice to get rid of the messages in /var/log/daemon.log saying

Started Proxmox VE Replication Runner
pvesr.timer: Succeeded

# systemctl stop pvesr.timer
# systemctl disable pvesr.timer

# systemctl stop pve-cluster.service
# systemctl disable pvesr.timer