I know someone who did setup ceph just for it's healing capabilities.. but of course one has to familiarize with all of it's administration aspects for that.

Setups with RAID1 could help fixing bit rot, but I think these setups are not full stack tested, so one would have to play and test by oneself (and after soft ware updates verify the whole stack again..).

Maybe easiest remedy is to keep all files in a second directory, and hope that when bit rot invalidates one version of the file the second one is ok. rsync could in cycles sync the 2 directory trees.