Enable Hyprland, fix locale, clean up chromium flags, fix README
- Enable programs.hyprland via new nixos desktop module
- Remove redundant en_US locale alongside "all"
- Drop stale --enable-features=UseOzonePlatform chromium flag
- Fix nixpkgs.config.allowUnfree typo in README
Co-Authored-By: Claude Sonnet 4.6 noreply@anthropic.com