Add home-manager config for sonja from ~/.config/home-manager

Moves home-manager configuration into the flake under home/sonja/,
integrating git, GPG agent, and package config. Fixes deprecated
home-manager options and removes nixpkgs.config override incompatible
with useGlobalPkgs.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

hosts/coven/configuration.nix

@@ -91,39 +91,7 @@
   # home-manager module is injected by the flake; no need to import it here
   home-manager.useGlobalPkgs   = true;
   home-manager.useUserPackages = true;
-  home-manager.users.sonja = { pkgs, lib, ... }: {
-    nixpkgs.config.allowUnfreePredicate = pkg:
-      builtins.elem (lib.getName pkg) [
-        "discord"
-        "steam-unwrapped"
-        "steam"
-        "steam-original"
-        "steam-run"
-        "steamcmd"
-        "steam-tui"
-        "claude-code"
-      ];
-
-    home.packages = [
-      pkgs.librewolf
-      pkgs.zsh
-      pkgs.neovim
-      pkgs.nmap
-      pkgs.alacritty
-      pkgs.tmux
-      pkgs.git
-      pkgs.uv
-      pkgs.discord
-      pkgs.steam-unwrapped
-      pkgs.steam-tui
-      pkgs.supersonic
-      pkgs.fzf
-      pkgs.gnupg
-      pkgs.claude-code
-    ];
-
-    home.stateVersion = "25.11";
-  };
+  home-manager.users.sonja     = import ../../home/sonja/home.nix;
 
   programs.ssh.extraConfig = ''
     Host whatbox