home/fonts.nix only set fonts.fontconfig.enable = true, which home-manager
enables automatically when font packages are declared. Delete the file and
remove its imports from both host home.nix files.
Replaces the monolithic packages-marvin.nix with one file per program
so hosts can opt in selectively. Adds docker, clamav, steam, and
audio keybindings for hivebrain. Fixes monitor order and switches
volume widget to PulseVolume.
Add a second nixosConfigurations entry for a friend's machine running
Plasma 6 + SDDM. The hardware-configuration.nix is a placeholder; it
must be replaced with the output of nixos-generate-config on the
actual hardware before installing. Git identity in hosts/nikita-nixos/
home.nix is also a placeholder.