- Add hyprlock module and package plus hyprlock.conf XDG config
- Rework bindings: introduce mkMenu, gui/term helpers and grouped
menus (apps, dev, gaming, utility, system) and wire them into the
main popup; change session lock to hyprlock
- Simplify gaming-apps.nix: use pkgs, reorder packages and add
wineWow64Packages.staging, steam-run and appimage-run