Two quick QOL updates for bkup:

1. A new flag --full which does a full (non-incremental) backup whether or not there is a .date/.date.gpg file. This sets --rsync-mode=sync as well.
2. A new flag --write-decrypted to write the decrypted .salt and .date files in ${XDG_DATA_DIR} (these will never be stored in ${XDG_CACHE_DIR}, so they are never uploaded to the cloud).

The first is useful for cases where the contents change quite frequently (e.g. ~/.config), since incremental backups will inflate the storage quite quickly. The second is useful if, like me, you repeatedly forget to decrypt the salt and date files for any newly-backed-up directories.

Next up is probably writing some kind of restore script. In all fairness, restoring is pretty easy: decrypt each chunk, cat them together, run it through zstd -d and then tar -xf (that was the reasoning behind using standard formats like tar and gpg after all). Still, having some kind of restore script is probably a good idea.