They are compiled native program add-ons we bundle for Electron to be able to implement some native functionality that by default isn’t available. Think of them like .dll files.
What’s happening here is that our app is bundled into a zip file, which can’t run native addons directly, so the engine unpacks it into the temp folder.
What I can do for the next version is to build it unpacked so it will reside next to the executable.
A fix will be available starting from v0.8.6 - you’ll need to reinstall using the full installer once that’s publicly released since our auto-updater doesn’t touch native addons.