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/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)
     };
 }