template backup ran a full multi-GB, multi-minute 7z pass over every
template every night regardless of whether anything under it had actually
changed -- the systemd unit's own comment already noted the resulting
archives were byte-identical run to run. Now compares the template dir's
newest file mtime against its most recent existing backup and skips the
compress step (still honoring --keep-count via prune) when nothing is
newer. --force opts back into an unconditional backup.
Simone
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