remove default for clan.core.settings.machine.name and make readOnly

There is not reason that there needs to be a default. Machines are usually defined as an attrset, so there is no reason to have a default.
Also make this readOnly as we never want to override it.

checks/lib/container-test.nix

@@ -9,10 +9,17 @@ in
   {
     hostPkgs = pkgs;
     # speed-up evaluation
-    defaults = {
+    defaults =
+      { config, options, ... }:
+      {
         imports = [
           ./minify.nix
         ];
+        config = lib.mkMerge [
+          (lib.optionalAttrs (options ? clan) {
+            clan.core.settings.machine.name = config.networking.hostName;
+          })
+          {
             documentation.enable = lib.mkDefault false;
             boot.isContainer = true;
 
@@ -31,6 +38,8 @@ in
 
             # we don't have permission to set cpu scheduler in our container
             systemd.services.nix-daemon.serviceConfig.CPUSchedulingPolicy = lib.mkForce "";
+          }
+        ];
       };
     # to accept external dependencies such as disko
     node.specialArgs.self = self;

checks/lib/test-base.nix

@@ -8,15 +8,22 @@ in
   hostPkgs = pkgs;
   # speed-up evaluation
   defaults = (
-    { config, ... }:
+    { config, options, ... }:
     {
       imports = [
         ./minify.nix
       ];
+      config = lib.mkMerge [
+        (lib.optionalAttrs (options ? clan) {
+          clan.core.settings.machine.name = config.networking.hostName;
+        })
+        {
           documentation.enable = lib.mkDefault false;
           nix.settings.min-free = 0;
           system.stateVersion = config.system.nixos.release;
         }
+      ];
+    }
   );
 
   _module.args = { inherit self; };

lib/build-clan/module.nix

@@ -94,9 +94,6 @@ let
               # Inherited from clan wide settings
               # TODO: remove these
 
-              # Machine specific settings
-              # clan.core.settings.machine.name = name;
-
               networking.hostName = lib.mkDefault name;
 
               # For vars we need to override the system so we run vars

nixosModules/clanCore/metadata.nix

@@ -117,7 +117,7 @@ in
               options = {
                 name = mkOption {
                   type = types.str;
-                  default = "nixos";
+                  readOnly = true;
                   description = ''
                     the name of the machine
                   '';