feat: nomarchy-install — guided live-ISO installer (disko + mkFlake)

Ported from the previous iteration's installer (3bdfc35), adapted to the
mkFlake world. gum TUI: disk pick, optional LUKS2, user/hostname/timezone,
DMI → nixos-hardware autodetection (hardware-db.sh). disko partitions
GPT + 1 GiB ESP + BTRFS subvolumes; the generated machine flake lands at
~user/.nomarchy (one mkFlake call, /etc/nixos symlinks to it) and
nixos-install makes it bootable (UEFI/systemd-boot, v1 single disk).

Offline by construction: the target flake.lock is composed from the rev
the ISO was built from (compose-lock.py), `nix flake archive` seeds the
target store, and the ISO pre-builds the template system + desktop.
First boot lands themed: the HM generation is pre-activated in chroot.

mkFlake grows two things for this: hardwareProfile now also takes a list
(autodetection emits several common-* modules), and installed systems get
the standalone home-manager CLI from the pinned input. Unattended mode
(NOMARCHY_UNATTENDED=1 + env) documented in docs/TESTING.md §4.

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

lib.nix

@@ -9,23 +9,28 @@
   mkFlake =
     { src                      # the downstream flake directory (./.)
     , username                 # login name; also the homeConfigurations attr
-    , hardwareProfile ? null   # a nixos-hardware module name, or null
+    , hardwareProfile ? null   # nixos-hardware module name(s): string, list, or null
     , system ? "x86_64-linux"
     }:
     let
       inherit (nixpkgs) lib;
 
-      hardwareModules =
-        if hardwareProfile == null then
-          [ ]
-        else if builtins.hasAttr hardwareProfile nixos-hardware.nixosModules then
-          [ nixos-hardware.nixosModules.${hardwareProfile} ]
+      # One profile or several (the installer's autodetection emits a few
+      # common-* modules alongside the model-specific one).
+      profileNames =
+        if hardwareProfile == null then [ ]
+        else if builtins.isList hardwareProfile then hardwareProfile
+        else [ hardwareProfile ];
+
+      lookupProfile = name:
+        if builtins.hasAttr name nixos-hardware.nixosModules then
+          nixos-hardware.nixosModules.${name}
         else
           throw ''
-            nomarchy.lib.mkFlake: unknown hardwareProfile "${hardwareProfile}".
+            nomarchy.lib.mkFlake: unknown hardwareProfile "${name}".
             ${let
                 close = builtins.filter
-                  (name: lib.strings.levenshteinAtMost 3 name hardwareProfile)
+                  (candidate: lib.strings.levenshteinAtMost 3 candidate name)
                   (builtins.attrNames nixos-hardware.nixosModules);
               in
               lib.optionalString (close != [ ])
@@ -37,6 +42,8 @@
             Omit hardwareProfile entirely if your machine has no profile.
           '';
 
+      hardwareModules = map lookupProfile profileNames;
+
       pkgs = import nixpkgs {
         inherit system;
         overlays = [ nomarchy.overlays.default ];
@@ -49,7 +56,13 @@
         inherit system;
         specialArgs = { inherit username; };
         modules =
-          [ nomarchy.nixosModules.nomarchy ]
+          [
+            nomarchy.nixosModules.nomarchy
+            # The standalone HM CLI ships with the system so theme switching
+            # (`nomarchy-theme-sync apply` → `home-manager switch`) works
+            # out of the box — same pinned input as the desktop modules.
+            { environment.systemPackages = [ home-manager.packages.${system}.home-manager ]; }
+          ]
           ++ hardwareModules
           ++ [
             (src + "/hardware-configuration.nix") # from nixos-generate-config