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.
Split the packages by platform so each app stays an opt-in Stow package
under common/, mac/ or kde/. KDE gets its own Fastfetch, Helium and
Spectacle packages, and darwin-breeze becomes kde/theme. The READMEs
document stowing a whole group as well as individual packages.