move nixos-facter imports to clanCore

nixosModules/clanCore/default.nix

@@ -9,6 +9,7 @@
     ./meta/interface.nix
     ./metadata.nix
     ./networking.nix
+    ./nixos-facter.nix
     ./nix-settings.nix
     ./options.nix
     ./outputs.nix

nixosModules/clanCore/nixos-facter.nix

@@ -0,0 +1,24 @@
+{ lib, config, ... }:
+let
+  directory = config.clan.core.clanDir;
+  inherit (config.clan.core) machineName;
+  facterJson = "${directory}/machines/${machineName}/facter.json";
+  hwConfig = "${directory}/machines/${machineName}/hardware-configuration.nix";
+in
+{
+  facter.reportPath = lib.mkIf (builtins.pathExists facterJson) facterJson;
+  warnings =
+    lib.optionals
+      (builtins.all builtins.pathExists [
+        hwConfig
+        facterJson
+      ])
+      [
+        ''
+          Duplicate hardware facts: '${hwConfig}' and '${facterJson}' exist.
+          Using both is not recommended.
+
+          It is recommended to use the hardware facts from '${facterJson}', please remove '${hwConfig}'.
+        ''
+      ];
+}