Rewrite my ./generated/modules/traveldroid/desktop/stylix.nix  to integrate nicely with my existing flake.nix en host.nix
The only real change is that the following needs to be added on userlevel:

stylix.targets.gtk.enable = true;


------------------------------------------------------------------------
{ lib, config, pkgs, flakeRoot, ... }:
let # Determine the default username from host
config username = config.defaultUser or "henrov";
moduleName = "stylix";
assetPath = "${flakeRoot}/assets/traveldroid/conf/";

# Read all files in the asset directory
programFiles = builtins.readDir assetPath;
files = lib.genAttrs (builtins.attrNames programFiles) (name: { source = "${assetPath}/${name}"; });
# Optional stylix.conf
stylixConfFile = "${assetPath}/stylix.conf";
stylixConf = if builtins.pathExists stylixConfFile then builtins.readFile stylixConfFile else "";
# Cursor defaults
cursorName = "phinger-cursors-light";
cursorSize = 24;
in
{
  ############################ # System-level packages ############################
  environment.systemPackages = [ pkgs.feh pkgs.st ];
  # ############################ # Home Manager user config ############################
  _module.args.hmUsers = { ${username} = {
      # Map all config files into ~/.config/stylix/
      xdg.configFile = lib.mapAttrs'
        (name: value: { name = "${moduleName}/${name}";
          value = { inherit (value) source; };
        }) files;

        # Environment variables for the session
        home.sessionVariables = {
          STYLIX_CONF = "$HOME/.config/stylix/stylix.conf";
          XCURSOR_THEME = cursorName;
          XCURSOR_SIZE = toString cursorSize;
          HYPRCURSOR_THEME = cursorName;
          HYPRCURSOR_SIZE = toString cursorSize;
        };
    };
  };
}
------------------------------------------------------------------------

flake.nix

{
  description = "Droidnix: A dendritic NixOS + Home Manager configuration";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";

    home-manager = {
      url = "github:nix-community/home-manager";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    import-tree.url = "github:vic/import-tree";

    stylix = {
      url = "github:nix-community/stylix";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    zen-browser = {
      url = "github:youwen5/zen-browser-flake";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    hyprland.url = "github:hyprwm/Hyprland";
  };

  outputs = { self, nixpkgs, home-manager, import-tree, stylix, hyprland, zen-browser, ... }:
    let
      system = "x86_64-linux";
      flakeRoot = self;
    in {
      nixosConfigurations = {
        traveldroid = nixpkgs.lib.nixosSystem {
          inherit system;

          modules = [
            ./generated/hosts/traveldroid/host.nix
          ];

          specialArgs = {
            inherit flakeRoot;
            inherit home-manager import-tree stylix hyprland zen-browser;
          };
        };
      };
    };
}

------------------------------------------------------------------------

host.nix

{ lib, config, pkgs, flakeRoot, import-tree, home-manager, ... }:

let
  hostname = "traveldroid";

  modulesPath = "${flakeRoot}/generated/modules/${hostname}";
  usersPath   = "${flakeRoot}/generated/users";

  hostModules = import-tree modulesPath;
  globalUsers = import-tree usersPath;

  allModules = hostModules.imports ++ globalUsers.imports;

in
{
  #################################
  # Core system config
  #################################

  networking.hostName = hostname;
  system.stateVersion = "26.05";

  #################################
  # Imports
  #################################

  imports =
    [
      ./boot.nix
      ./hardware-configuration.nix

      # REQUIRED for Home Manager
      home-manager.nixosModules.home-manager
    ]
    ++ allModules;

  #################################
  # Home Manager integration
  #################################

  home-manager.useGlobalPkgs = true;
  home-manager.useUserPackages = true;
}