update

- `chbg`: avoid null argument
- `fake-nautilus` overrides.

bin/chbg

@@ -1,5 +1,7 @@
 #!/bin/bash
 # to change wallpapers both niri workspace and niri tab view
+[ -z "$1" ] && { echo "Usage: $0 <image-file>"; exit 1; }
+
 WP_DIR="$HOME/.local/share"
 
 echo -n "making blurred version... "