Can I run a Malairte node on a Raspberry Pi or mini PC?

Yes, and it is a popular choice. A node is modest in its needs once synced: validation is light, memory use is low, and the CPU only works hard during the initial sync. A small single-board computer or a low-power mini PC handles a node comfortably and sips only a few watts, which matters because the node runs every hour of every day. The main requirement is a solid-state drive with generous free space, since disk is the real constraint. Pair that with a normal internet connection and you have an always-on node you can tuck away and forget.