We already have the --gameDir argument, but we're missing the --assetsDir which is not always $gameDir/assets. In development, this is located in ~/.gradle. In the vanilla launcher, it is always ~/.minecraft/assets no matter where the game dir is. This used to be accessible via Launcher.assetsDir, but this is not available in Knot.

A simple mixin to access it from MinecraftClient would work, but it really should be a dedicated class that can hold these paths.

Closing since this has been resolved via a recent fabric loader PR to get the game's launch args.