I restored the forum database from one of the numerous backups my host keeps (another reason to love them — it turns out they keep multiple backups going back as far as 10 months, and you can actually restore them yourself from the web panel!), and all appears well now.

However, I’m keeping the forums disabled for the next few days just because I still need to install the phpBB security upgrade, and I know that’s going to take a little while, and I don’t want an instant replay in the meantime.

Hopefully I’ll have the forums upgraded and back up by Monday.