feat: nomarchy.lib.mkFlake — one-call downstream wrapper + hardware profiles

Downstream users now own only system.nix and home.nix; their flake.nix is
generated once from the template and never hand-edited. mkFlake (lib.nix)
wires both layers and maps hardwareProfile = "<name>" to nixos-hardware
modules (new input, pinned here, nixpkgs follows ours; unknown names fail
with did-you-mean suggestions). Flake checks evaluate the template through
mkFlake — including a real profile — so drift fails `nix flake check`.

Also from the live-VM testing session: install the home-manager CLI in the
live ISO and pin flake inputs transitively (offline theme switching needs
stylix's own inputs too), plus swww→awww doc updates.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

templates/downstream/README.md

@@ -1,8 +1,13 @@
 # My Nomarchy machine
 
-1. `nixos-generate-config --show-hardware-config > hardware-configuration.nix`
-2. Edit `flake.nix` (Nomarchy repo URL, username), `system.nix` (hostname,
-   user), `home.nix` (your packages).
+1. Overwrite the placeholder hardware config with the real one:
+   `nixos-generate-config --show-hardware-config > hardware-configuration.nix`
+2. Set `flake.nix` up **once** (Nomarchy repo URL, your username, optionally
+   a `hardwareProfile` from <https://github.com/NixOS/nixos-hardware> — an
+   unknown name fails the rebuild with suggestions). After that the flake is
+   never touched again: your machine lives in `system.nix` (hostname,
+   services — the login user is created from `username` automatically) and
+   `home.nix` (your packages).
 3. `git init && git add -A` — flakes only see tracked files, including
    `theme-state.json`.
 4. System: `sudo nixos-rebuild switch --flake .#default`

templates/downstream/flake.nix

@@ -1,53 +1,20 @@
 {
   description = "My Nomarchy machine";
 
-  inputs = {
-    # Pin Nomarchy; nixpkgs and home-manager follow whatever it ships.
-    nomarchy.url = "github:YOUR-USER/nomarchy"; # <- point at the distro repo
-    nixpkgs.follows = "nomarchy/nixpkgs";
-    home-manager.follows = "nomarchy/home-manager";
-  };
+  # The only input. nixpkgs, home-manager etc. come pinned through it —
+  # tested together upstream. This file is written once (by you or the
+  # installer) and never hand-edited afterwards; your machine lives in
+  # system.nix and home.nix.
+  inputs.nomarchy.url = "github:YOUR-USER/nomarchy"; # <- the distro repo
 
-  outputs = { self, nomarchy, nixpkgs, home-manager, ... }:
-    let
-      system = "x86_64-linux";
+  outputs = { nomarchy, ... }:
+    nomarchy.lib.mkFlake {
+      src = ./.;
       username = "me"; # <- your login name
 
-      pkgs = import nixpkgs {
-        inherit system;
-        overlays = [ nomarchy.overlays.default ];
-      };
-    in
-    {
-      # System layer — rebuilt rarely:
-      #   sudo nixos-rebuild switch --flake .#default
-      nixosConfigurations.default = nixpkgs.lib.nixosSystem {
-        inherit system;
-        modules = [
-          nomarchy.nixosModules.nomarchy   # the distro
-          ./hardware-configuration.nix     # from `nixos-generate-config`
-          ./system.nix                     # your machine
-        ];
-      };
-
-      # Desktop layer — rebuilt on every theme change, no sudo:
-      #   home-manager switch --flake .#me
-      # (`nomarchy-theme-sync apply <theme>` runs this for you.)
-      homeConfigurations.${username} = home-manager.lib.homeManagerConfiguration {
-        inherit pkgs;
-        modules = [
-          nomarchy.homeModules.nomarchy
-          ./home.nix
-          {
-            # Your theme state — written by nomarchy-theme-sync, baked
-            # in on every switch. Keep it git-tracked.
-            nomarchy.stateFile = ./theme-state.json;
-            home = {
-              inherit username;
-              homeDirectory = "/home/${username}";
-            };
-          }
-        ];
-      };
+      # Optional: a nixos-hardware module name for your machine, e.g.
+      #   hardwareProfile = "framework-13-7040-amd";
+      # Names: https://github.com/NixOS/nixos-hardware
+      # (the future installer fills this in automatically from DMI data)
     };
 }

templates/downstream/hardware-configuration.nix

@@ -0,0 +1,15 @@
+# PLACEHOLDER — replace with the output of `nixos-generate-config` on the
+# target machine. The mkDefault values below only exist so the flake
+# evaluates and `nix flake check` passes before first install.
+{ lib, ... }:
+
+{
+  boot.initrd.availableKernelModules = lib.mkDefault [ "xhci_pci" "ahci" "nvme" "usbhid" "sd_mod" ];
+
+  fileSystems."/" = lib.mkDefault {
+    device = "/dev/disk/by-label/nixos";
+    fsType = "ext4";
+  };
+
+  nixpkgs.hostPlatform = lib.mkDefault "x86_64-linux";
+}

templates/downstream/system.nix

@@ -2,7 +2,7 @@
 # The distro itself comes from nomarchy.nixosModules.nomarchy — override
 # any of its defaults here with plain NixOS options (they use mkDefault),
 # or via the nomarchy.system.* toggles.
-{ pkgs, ... }:
+{ pkgs, username, ... }:
 
 {
   boot.loader.systemd-boot.enable = true;
@@ -12,7 +12,8 @@
   time.timeZone = "UTC";
   i18n.defaultLocale = "en_US.UTF-8";
 
-  users.users.me = { # <- keep in sync with `username` in flake.nix
+  # Your login user — `username` flows in from flake.nix automatically.
+  users.users.${username} = {
     isNormalUser = true;
     extraGroups = [ "wheel" "networkmanager" "video" "input" ];
   };