Adds multiple named remotes. Each folder selects its server, and an
unreachable host no longer blocks the others. Transfers resume safely,
SSH host keys are pinned, and 0.1.x settings retain every safe entry.
Mirror deletions run only after transfer and are reported. Scheduling
survives reboots without duplicate jobs. Includes rsync 3.5.0 security
fixes and 16 KB page-size support.
