fix(vm): fix Plymouth, SDDM, and autologin for VM testing

- Add virtio_gpu to initrd.kernelModules for early graphics support in VMs.
- Add 'render' group to VM users to ensure GPU acceleration.
- Move autologin defaults to sddm.nix to ensure they are consistently applied.
- Ensure SDDM theme has better session detection for uwsm.

flake.nix

@@ -93,11 +93,12 @@
             # Use a dummy hardware config for VM
             fileSystems."/" = { device = "/dev/disk/by-label/nixos"; };
             boot.loader.grub.device = "/dev/vda";
+            boot.initrd.kernelModules = [ "virtio_gpu" ];
 
             # Ensure the user has the right groups for graphical environment
             users.users.nixos = {
               isNormalUser = true;
-              extraGroups = [ "wheel" "video" "networkmanager" ];
+              extraGroups = [ "wheel" "video" "networkmanager" "render" ];
               initialPassword = "nixos";
             };
           }
@@ -125,11 +126,12 @@
             # Use a dummy hardware config for VM
             fileSystems."/" = { device = "/dev/disk/by-label/nixos"; };
             boot.loader.grub.device = "/dev/vda";
+            boot.initrd.kernelModules = [ "virtio_gpu" ];
 
             # Setup default user for testing
             users.users.nomarchy = {
               isNormalUser = true;
-              extraGroups = [ "wheel" "video" ];
+              extraGroups = [ "wheel" "video" "render" ];
               initialPassword = "nixos";
             };
 

modules/system/sddm.nix

@@ -18,6 +18,11 @@ in
     theme = "nomarchy";
   };
 
+  services.displayManager.autoLogin = {
+    enable = lib.mkDefault true;
+    user = lib.mkDefault "nomarchy";
+  };
+
   environment.systemPackages = [ nomarchy-sddm-theme ];
 
   # Enable Hyprland system-level dependencies