LabCraft Closures: a new hands-on Nix Part about what upgrades actually move

I’ve published Closures, the next free Part of LabCraft’s Nix course. It focuses on the operational unit behind Nix copies, caches, deploys, and images: the closure. The lab starts from a familiar mistake, copying one store path as if it were the whole thing, then asks learners to predict what an upgrade actually moves before Nix shows them the answer. The post is here: I’m building LabCraft and would welcome feedback from Nix users on whether this framing lands for newer learners.