refactor(fastfetch): merge the mac and kde configs into common

One Fastfetch package now serves both platforms. The logo is sent
inline through the kitty graphics protocol from a pre-encoded
albedo.kitty, which works in Ghostty and Kwi alike, so the separate
kitty-direct (mac) and Konsole (kde) variants are no longer needed.

mac/README.md

@@ -6,16 +6,10 @@ From the repository root, install all macOS packages:
 (cd mac && stow -t "$HOME" */)
 ```
 
-Or choose individual packages:
+Install the package:
 
 ```sh
 stow -d mac -t "$HOME" ghostty
-stow -d mac -t "$HOME" fastfetch
 ```
 
 - `ghostty`: JetBrainsMono Nerd Font and Ghostty's bundled SpaceGray Eighties theme.
-- `fastfetch`: the original configuration, with a `kitty-direct` image logo.
-  Its source PNG is included in `fastfetch/.config/fastfetch/`.
-
-These packages are independent. Choose either `mac/fastfetch` or
-`kde/fastfetch`; both own `~/.config/fastfetch/`.