Backups collected before markers became assets were filed against the operation
number the PC reported. The collector now files a marker PC's backup against
its marker, but only for backups collected since; everything already stored
stayed where it was, so the new marker assets read as empty while the operation
holds a mixed history.
The attribution is exact rather than a guess. A revision records the PC it was
read from, and the collector records which marker each PC drives, so the move
is that mapping applied. Revisions with no source hostname stay put, since
nothing says which marker they came from.
Moving a revision can duplicate one the collector has already written against
the marker, so the script collapses those as part of the move, keeping the
earliest so the date a config was first seen survives. Dry run by default.
