Add qbittorrent and drop zen kernel

systems/gandalf/default.nix

@@ -20,6 +20,7 @@
       ../modules/audacity.nix
       ../modules/ollama.nix
       ../modules/wireguard.nix
+      ../modules/qbittorrent.nix
     ];
 
   boot.loader.systemd-boot.enable = true;
@@ -50,12 +51,6 @@
 
   virtualisation.libvirtd.enable = true;
 
-  specialisation = {
-    zen.configuration = {
-      boot.kernelPackages = pkgs.linuxPackages_zen;
-    };
-  };
-
   services = {
     # Bluetooth fixes
     # Can be removed when https://github.com/NixOS/nixpkgs/pull/499670 is merged and in 25.11

systems/modules/qbittorrent.nix

@@ -0,0 +1,7 @@
+{ pkgs, ... }: 
+
+{
+  environment.systemPackages = with pkgs; [
+    qbittorrent
+  ];
+}