Switch desktop environment from Hyprland to Pantheon

Configures Pantheon (LightDM + gala) for daily use on this ASUS TUF
Gaming A15 (FA507NU), and drops everything that only existed to serve
the previous Hyprland/Quickshell setup:

- desktop.nix: services.desktopManager.pantheon instead of
  programs.hyprland + greetd; comfy laptop touchpad defaults.
- drivers.nix: NVIDIA PRIME render offload between the AMD Radeon 680M
  (drives the panel) and the RTX 4050 Max-Q (offload-only), using this
  machine's real PCI bus IDs; asusd/supergfxd for ASUS-specific laptop
  control.
- apps.nix / scripts.nix: removed Hyprland/Quickshell-only packages and
  scripts (kitty, rofi, quickshell, mako, hyprlock, hyprpaper/mpvpaper,
  the Quickshell theme-picker scripts, cursor/wallpaper/display
  helpers) — Pantheon ships its own Files/Terminal/Screenshot/
  notifications/theming natively. Kept the DE-agnostic scripts (vault
  toggle, metadata stripping, brightness control, Wi-Fi hotspot,
  telemetry, weather).
- theme.nix and default-apps.nix deleted entirely — Pantheon owns
  GTK/icon theming itself, no more live dconf/CSS generation pipeline
  needed.
- Deleted hyprland/ and dotfiles/ (kitty, mako, quickshell, rofi).

Verified with `nixos-rebuild build`.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RpiovBQL6k5MTDMN3Ln9nL

modules/users.nix

@@ -0,0 +1,27 @@
+{ config, pkgs, ... }:
+
+{
+  # Primary user account configuration (Access and settings only)
+  users.users."nexoniarz" = {
+    isNormalUser = true;
+    description = "Nexoniarz";
+    extraGroups = [ "networkmanager" "wheel" "fuse" "i2c" "video" ];
+    shell = pkgs.zsh;
+  };
+
+  # Default shell (ZSH)
+  programs.zsh.enable = true;
+
+  # Web browser configuration
+  programs.firefox.enable = true;
+
+  # Enable Steam with optimized system configurations
+  programs.steam = {
+    enable = true;
+    remotePlay.openFirewall = true;
+    dedicatedServer.openFirewall = true;
+  };
+
+  # Enable Flatpak support
+  services.flatpak.enable = true;
+}