When hardwareProfile includes common-gpu-nvidia, emit a comment-only
plain NixOS block (PRIME / powerManagement / open-module) in the
installer region of system.nix — same pattern as ROCm/NPU opt-ins.
HARDWARE.md §6 product direction marked shipped. Close#59.
Verified: V0 (patch-template smoke + negative + bash -n).
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.
