MarsSeed [1] filed a deletion request for citadel [2]: Abandoned, unused package from 2016. OOD flag ignored since 2021. Last comment is from 2016.
At this point it seems safe to delete due to lack of relevance for AUR users. [1] https://aur.archlinux.org/account/MarsSeed/ [2] https://aur.archlinux.org/pkgbase/citadel/
