add nvidia and prime to citadel

hosts/citadel/default.nix

@@ -71,10 +71,12 @@ in {
     };
   };
 
-  swapDevices = [ {
+  swapDevices = [
+    {
       device = "/.swapvol/swapfile";
       size = 32 * 1024;
-   } ];
+    }
+  ];
 
   services = {
     libinput.touchpad.accelSpeed = "0.5";
@@ -123,6 +125,41 @@ in {
     ];
   };
 
+  # nvidia
+  hardware.opengl = {
+    enable = true;
+  };
+
+  services.xserver.videoDrivers = ["nvidia"];
+
+  hardware.nvidia = {
+    prime = {
+      offload = {
+        enable = true;
+        enableOffloadCmd = true;
+      };
+      intelBusId = "PCI:0:2:0";
+      nvidiaBusId = "PCI:1:0:0";
+    };
+    modesetting.enable = true;
+    powerManagement.enable = false;
+    powerManagement.finegrained = false;
+    open = false;
+    nvidiaSettings = true;
+    # FIXME issue with stable nvidia driver and latest linux kernel
+    # use mkDriver to specify newer nvidia driver that is compatible
+    # see: https://github.com/NixOS/nixpkgs/issues/341844#issuecomment-2351075413
+    # and https://discourse.nixos.org/t/builder-for-nvidia-x11-550-78-6-10-drv-failed-with-exit-code-2/49360/32
+    package = config.boot.kernelPackages.nvidiaPackages.mkDriver {
+      version = "555.58.02";
+      sha256_64bit = "sha256-xctt4TPRlOJ6r5S54h5W6PT6/3Zy2R4ASNFPu8TSHKM=";
+      sha256_aarch64 = "sha256-wb20isMrRg8PeQBU96lWJzBMkjfySAUaqt4EgZnhyF8=";
+      openSha256 = "sha256-8hyRiGB+m2hL3c9MDA/Pon+Xl6E788MZ50WrrAGUVuY=";
+      settingsSha256 = "sha256-ZpuVZybW6CFN/gz9rx+UJvQ715FZnAOYfHn5jt5Z2C8=";
+      persistencedSha256 = "sha256-a1D7ZZmcKFWfPjjH1REqPM5j/YLWKnbkP9qfRyIyxAw=";
+    };
+  };
+
   networking = {
     hostName = "citadel";
     networkmanager.enable = true;