enable nh for easier management

nixos/common/default.nix

@@ -18,11 +18,12 @@
       ];
     };
 
-    gc = {
-      automatic = true;
-      dates = "weekly";
-      options = "--delete-older-than +3";
-    };
+    # disabled in favour of nh
+    # gc = {
+    #   automatic = true;
+    #   dates = "weekly";
+    #   options = "--delete-older-than +3";
+    # };
   };
 
   users.users.lu.extraGroups = ["audio"];
@@ -31,6 +32,15 @@
   services.devmon.enable = true;
   services.gvfs.enable = true;
   services.udisks2.enable = true;
+
+  # set up a keyring
   services.gnome.gnome-keyring.enable = true;
   security.pam.services.hyprland.enableGnomeKeyring = true;
+
+  # use nh for easier nix stuff
+  programs.nh = {
+    enable = true;
+    clean.enable = true;
+    clean.extraArgs = "--keep 3";
+  };
 }