feat(install): copy templates/downstream and patch install values

Make the downstream template the single source of truth for machine
flakes: nomarchy-install copies flake/system/home/theme-state and
patch-template.py only fills hostname, user, keyboard, detected
hardware, snapper, resume, and password. Install and flake-init users
now share the same commented opt-ins and starter home.packages.

Also: BACKLOG boreal-as-default proposal; installer audit notes;
HARDWARE.md from prior work if uncommitted.

templates/downstream/flake.nix

@@ -5,6 +5,7 @@
   # 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. v1 is the release branch.
+  # Installer copies this template and patches username + hardwareProfile.
   inputs.nomarchy.url = "git+https://git.bemagri.xyz/bernardo/nomarchy.git?ref=v1";
 
   outputs = { nomarchy, ... }: