user.shell had nothing to do in a common module

hosts/box/user.nix

@@ -10,5 +10,6 @@ users.users.boxuser = {
     ];
   };
 
+users.users.boxuser.shell = pkgs.bash;
 users.groups.boxuser = {};
 }

hosts/puter/packages.nix

@@ -15,6 +15,7 @@
     ../../modules/userapps/productivity.nix
   ];
 
+  users.users.user.shell = pkgs.bash;
   users.users.user = {
     isNormalUser = true;
     description = "user";