Introduce 'cleanup', 'autoUpdate', and 'upgrade' options under the onActivation section for improved manageability. Additionally, remove unused homebrew configuration from modules/darwin/nix/default.nix.
Renamed several modules to better align with Darwin-specific configurations. Refactored configuration for Alacritty and removed it from system packages where not needed. Introduced Homebrew settings and cleaned up redundant entries in multiple Nix files.
This commit modifies the `nix` configuration in the `darwin` module, changing from the unstable `nix` package use to the stable version. This change is intended to improve stability and reliability of the module.
Harald Hoyer