nixosModules/clanCore: support nix-darwin

nixosModules/clanCore/vars/default.nix

@@ -1,4 +1,5 @@
 {
+  _class,
   lib,
   config,
   pkgs,
@@ -14,13 +15,16 @@ let
     };
 in
 {
-  imports = [
-    ./public/in_repo.nix
-    ./secret/fs.nix
-    ./secret/password-store.nix
-    ./secret/sops
-    ./secret/vm.nix
-  ];
+  imports =
+    [
+      ./public/in_repo.nix
+      ./secret/fs.nix
+      ./secret/sops
+      ./secret/vm.nix
+    ]
+    ++ lib.optionals (_class == "nixos") [
+      ./secret/password-store.nix
+    ];
   options.clan.core.vars = lib.mkOption {
     description = ''
       Generated Variables

nixosModules/clanCore/vars/secret/password-store.nix

@@ -52,6 +52,8 @@ let
 
 in
 {
+  _class = "nixos";
+
   options.clan.vars.password-store = {
     secretLocation = lib.mkOption {
       type = lib.types.path;