Add Home Manager options for user.js, userChrome.js, and other Zen-compatible configurations

[luisnquin]

This is an idea that has been on my mind over the past few weeks, especially after introducing sine (which is still currently broken). The general goal is to make it easier to extend user configurations through simple option toggles in Home Manager.

The concept is to provide optional integrations that can enable curated configuration sets compatible with Zen Browser. Instead of requiring users to manually manage large user.js files or additional customization scripts, the flake could expose structured options that enable these configurations declaratively.

Potential upstream configuration sources could include:

arkenfox – https://github.com/arkenfox/user.js
Schizofox – https://github.com/schizofox/schizofox
Betterfox – https://github.com/yokoffing/Betterfox

The idea would be to expose these as optional modules or presets that users can enable through Home Manager options, rather than forcing manual configuration.

This approach would require significant testing and probably some automation to ensure compatibility with Zen and avoid configuration conflicts. It may also make sense to mark these integrations as experimental, since they arguably fall slightly outside the core responsibility of the flake.

That said, for Nix users the declarative approach could be convenient and consistent with the ecosystem.

Feedback on the idea and possible implementation approaches would be appreciated.

[luisnquin]

Usage example:

programs.zen-browser = {
  enable = true;

  presets = {
    arkenfox.enable = true;
    betterfox.enable = false;
	catppuccin.enable = true;
  };
};

https://github.com/claymorwan/dotfiles/blob/main/NixOS/modules/home/Browsers/Zen/default.nix
alper-han/ZyNixOS@89fa32f#diff-fd9bf06d2eb3cc693e2947a19a8cb89b6911aa6e4e8f64d34d6f42112b7a5a3b
https://github.com/DADA30000/dotfiles/blob/main/modules/home/zen/default.nix