The reference catalog held 23,582 Thumbnail jobs, one per image, and
every scan re-coalesced all of them. Nothing has ever claimed that kind:
no JobHandler is registered for it on desktop or Android, and
dr_catalog::sync never merges another device's jobs in.
Thumbnails are owed by the store, not the queue. The grid's worker and
the thumbnail sweep both find their work by asking ThumbStore what it
lacks, and the store is shared between devices, so it is the only record
that knows another device already made one. A queue row was a second,
staler copy of that debt that grew with the library and was read by
nothing.
persist still writes the images and their remote identities in the one
transaction; it just no longer adds a row to jobs for each of them. The
two tests that asserted the rows existed become one that asserts a
repeated scan queues nothing.
Refs #73
dtourolle
5da28584a4