README: replace LD_PRELOAD with MOONGREET_NO_LAYER_SHELL env var, add missing features (GPU blur, journal logging, password wiping). build.rs: remove wallpaper.jpg reference. moongreet.toml: correct gtk-theme to Colloid-Grey-Dark-Catppuccin.
README: replace LD_PRELOAD with MOONGREET_NO_LAYER_SHELL env var, add missing features (GPU blur, journal logging, password wiping). build.rs: remove wallpaper.jpg reference. moongreet.toml: correct gtk-theme to Colloid-Grey-Dark-Catppuccin.