When the remote database is locked and the CLI device is not in the
accepted_nodes list, openReplication returns false with no CLI-specific
guidance. The existing log message ('Fetch rebuilt DB, explicit
unlocking or chunk clean-up is required') is aimed at the Obsidian
plugin UI.
Check the replicator's remoteLockedAndDeviceNotAccepted flag after
sync failure and print a clear message directing the user to unlock
from the Obsidian plugin.
Ref: #832
