final changes

nix/devshell.ulu.nix

@@ -16,21 +16,17 @@
           clippy
           rust-analyzer
           rustfmt
-          # Manual verification: grim is the pixel oracle, magick compares.
           grim
           imagemagick
           wayland-utils
         ];
 
-        # What the package gets through its RUNPATH, for `cargo run`.
         LD_LIBRARY_PATH = lib.makeLibraryPath [
           pkgs.wayland
           pkgs.libxkbcommon
           pkgs.libglvnd
         ];
 
-        # The repo is a path: flake, so Nix copies the whole tree on every
-        # evaluation. Keep the multi-gigabyte target dir out of it.
         shellHook = ''
           export CARGO_TARGET_DIR="''${XDG_CACHE_HOME:-$HOME/.cache}/valw/target"
         '';