Restructure flake.nix for a simpler config for building different images off the same NixOS config.

nix/configuration/roles/steam/default.nix

@@ -1,7 +1,6 @@
 {
   config,
   lib,
-  pkgs,
   ...
 }:
 
@@ -17,34 +16,30 @@
     };
   };
 
-  config = lib.mkIf config.me.steam.enable (
-    lib.mkMerge [
-      (lib.mkIf config.me.graphical {
-        allowedUnfree = [
-          "steam"
-          "steam-original"
-          "steam-unwrapped"
-          "steam-run"
+  config = lib.mkIf (config.me.steam.enable && config.me.graphical) {
+    allowedUnfree = [
+      "steam"
+      "steam-original"
+      "steam-unwrapped"
+      "steam-run"
+    ];
+
+    programs.steam = {
+      enable = true;
+      remotePlay.openFirewall = true; # Open ports in the firewall for Steam Remote Play
+      # dedicatedServer.openFirewall = true; # Open ports in the firewall for Source Dedicated Server
+      localNetworkGameTransfers.openFirewall = true; # Open ports in the firewall for Steam Local Network Game Transfers
+    };
+
+    environment.persistence."/persist" = lib.mkIf (config.me.mountPersistence) {
+      hideMounts = true;
+      users.talexander = {
+        directories = [
+          ".local/share/Steam"
+          ".steam"
+          ".factorio"
         ];
-
-        programs.steam = {
-          enable = true;
-          remotePlay.openFirewall = true; # Open ports in the firewall for Steam Remote Play
-          # dedicatedServer.openFirewall = true; # Open ports in the firewall for Source Dedicated Server
-          localNetworkGameTransfers.openFirewall = true; # Open ports in the firewall for Steam Local Network Game Transfers
-        };
-
-        environment.persistence."/persist" = lib.mkIf (!config.me.buildingIso) {
-          hideMounts = true;
-          users.talexander = {
-            directories = [
-              ".local/share/Steam"
-              ".steam"
-              ".factorio"
-            ];
-          };
-        };
-      })
-    ]
-  );
+      };
+    };
+  };
 }