Add the nix-homebrew input and darwin module so the Homebrew prefix is installed and owned declaratively (no manual bootstrap), with enableRosetta for x86_64 formulae on Apple Silicon and user = host username.
Set homebrew.onActivation.cleanup = zap so the taps/brews/casks/masApps lists are authoritative: anything not declared is removed on activation.
Turn on nix-darwin's homebrew module with empty taps/brews/casks/masApps lists to fill in, onActivation autoUpdate+upgrade, and cleanup=none (manual formulae left intact; flip to zap for fully authoritative lists). Set system.primaryUser so brew activation runs as the host user.
Add the nix-darwin input (nix-darwin-26.05, follows nixpkgs) and a mkDarwinHost mirroring mkHost: shared commonModule (nixpkgs/nix settings) is factored out and reused, home-manager is wired via darwinModules, and identity is threaded through specialArgs.
New darwinConfigurations.lyrathorpe-mac (aarch64-darwin) reuses the cross-platform ./lyrathorpe/home modules (shell, git, editor); Linux-only sway/desktop modules are excluded. Build with: darwin-rebuild switch --flake .#lyrathorpe-mac.
Emma Thorpe