fix: add flake.lock back and update host configs

- Added `flake.lock` to pin dependencies (nixpkgs, home-manager, nixvim, flake-utils, etc.)
- Cleaned up `.gitignore`: stop ignoring `*.lock`
- Removed unused `flake-utils.inputs.nixpkgs.follows`
- Nixstation host:
  - Removed `keychron.nix`, Wacom tablet config, and redundant session variables
  - Simplified GDM/GNOME configuration and XKB layout
  - Commented out virtualisation setup
- Common NVIDIA host config:
  - Added explicit kernel modules, parameters, blacklists, and kernel version
  - Ensured GNOME + GDM configuration present
  - Updated NVIDIA driver settings and CUDA support

hosts/Nixstation/default.nix

@@ -2,10 +2,8 @@
 , ...
 }:
 {
-
   imports = [
     ../common/default.nix
-    ../common/keychron.nix
     ../common/network.nix
     ../common/nvidia/default.nix
     ./hardware-configuration.nix
@@ -15,32 +13,6 @@
     loader.systemd-boot.enable = true;
     loader.efi.canTouchEfiVariables = true;
   };
-  environment.etc."libwacom/intuos4-4x6.tablet".text = ''
-    # Wacom
-    # Intuos4 Small
-    [Device]
-    Name=Wacom Intuos4 4x6
-    DeviceMatch=usb:056a:00b8
-    Class=Intuos4
-    Width=6
-    Height=4
-    Layout=intuos4-4x6.svg
-    IntegratedIn=
-    Styli=0x802;0x804;0x806;0x80a;0x80c;0x902;0x90a;0x100802;0x100804;0x10080a;0x10080c;0x100902;0x10090a;0x120802;0x140802;0x14080a;0x160802;0x16080a;
-
-    [Features]
-    Reversible=true
-    Stylus=true
-    Ring=true
-    Buttons=7
-    StatusLEDs=Ring
-
-    [Buttons]
-    Left=A;B;C;D;E;F;G
-
-    Ring=A
-    RingNumModes=4
-  '';
   environment = {
     systemPackages = with pkgs; [
       act
@@ -57,14 +29,8 @@
       NIXOS_HOST = "nixstation";
       NIXOS_DE = "wayland";
     };
-
-    sessionVariables = {
-      NIXOS_OZONE_WL = "1";
-      XDG_SESSION_TYPE = "wayland";
-      QT_QPA_PLATFORM = "wayland";
-      GDK_BACKEND = "wayland";
-    };
   };
+  
   hardware = {
     sane.enable = true;
     graphics.enable = true;
@@ -115,15 +81,15 @@
   security.rtkit.enable = true;
   services = {
     xserver = {
-      enable = true;
-      desktopManager.gnome.enable = true;
-      displayManager.gdm = {
-        enable = true;
-        wayland = true;
+      xkb = {
+        layout = "us";
+        variant = "alt-intl";
       };
-      displayManager.defaultSession = "gnome";
     };
-    
+    desktopManager.gnome.enable = true;
+    displayManager.gdm.enable = true;
+    displayManager.gdm.wayland = true;
+    displayManager.defaultSession = "gnome";
     udev.packages = [ pkgs.libwacom ];
     avahi = {
       enable = true;
@@ -178,16 +144,15 @@
   };
   system.stateVersion = "25.11"; # keep it!
   time.timeZone = "America/Sao_Paulo";
-  virtualisation = {
-    vmware.host.enable = false;
-    spiceUSBRedirection.enable = true;
-    libvirtd = {
-      enable = true;
-      qemu.ovmf.enable = true;
-      qemu.package = pkgs.qemu_full;
-    };
-
-  };
+  # virtualisation = {
+  #   vmware.host.enable = false;
+  #   spiceUSBRedirection.enable = true;
+  #   libvirtd = {
+  #     enable = true;
+  #     qemu.ovmf.enable = true;
+  #     # qemu.package = pkgs.qemu_full;
+  #   };
+  # };
 
   zramSwap = {
     enable = true;