Adds nix-community/stylix on its release-25.11 branch (master references
options that don't exist in 25.11's nixpkgs). autoEnable=false so
matugen keeps owning every app it currently themes; we only opt in to
the five targets matugen doesn't cover.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
