create shared group for all server services to manage all files

modules/nixos/system/default.nix

@@ -10,6 +10,7 @@
     ./auto-upgrade.nix
     ./doas.nix
     ./journald.nix
+    ./shared.nix
     ./user.nix
     ./timezone.nix
   ];

modules/nixos/system/shared.nix

@@ -0,0 +1,14 @@
+{ config, lib, ... }:
+{
+
+  config = lib.mkIf config.server {
+
+    # Create a shared group for many services
+    users.groups.shared = { };
+
+    # Give the human user access to the shared group
+    users.users.${config.user}.extraGroups = [ config.users.groups.shared.name ];
+
+  };
+
+}