Switch to the PC config layout: Plasma, Limine, shared configs/

Same modules and settings as nexoniarz-config-nixos; only hardware.nix
differs. Pantheon/LightDM -> Plasma 6/SDDM, systemd-boot -> Limine,
system.nix/drivers.nix split into focused modules, Firefox prefs and
fastfetch config in configs/.

Laptop hardware kept: AMD 680M + RTX 4050 PRIME offload (bus IDs
unchanged), NVIDIA suspend fix, asusd + supergfxd, tablet driver,
DualSense ERTM fix, laptop scripts (brightness, hotspot, telemetry,
weather). Dropped: GoPro v4l2loopback webcam, blueman.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

configuration.nix

@@ -1,18 +1,30 @@
-# Main NixOS configuration file importing modular configurations.
-
 { config, pkgs, ... }:
 
 {
   imports = [
-    ./hardware-configuration.nix   # Generated hardware scan results
-    ./modules/system.nix           # Bootloader, networking, time, sound, hardening, nix-ld
-    ./modules/drivers.nix          # AMD/NVIDIA hybrid graphics (PRIME) and ASUS laptop control
-    ./modules/desktop.nix          # Pantheon desktop environment (LightDM + gala)
-    ./modules/users.nix            # User accounts and global configurations
-    ./modules/apps.nix             # All installed packages: apps, CLI tools, dev toolchains
-    ./modules/scripts.nix          # Custom system scripts and helpers
+    ./hardware-configuration.nix
+
+    # Core system
+    ./modules/boot.nix
+    ./modules/networking.nix
+    ./modules/locale.nix
+    ./modules/nix-settings.nix
+    ./modules/security.nix
+
+    # Hardware
+    ./modules/hardware.nix
+    ./modules/audio.nix
+
+    # Desktop & user
+    ./modules/desktop.nix
+    ./modules/users.nix
+    ./modules/apps.nix
+    ./modules/default-apps.nix
+    ./modules/scripts.nix
+    ./modules/fastfetch.nix
+    ./modules/firefox.nix
   ];
 
   # Do not change this value. Read documentation before updating.
-  system.stateVersion = "26.05"; 
+  system.stateVersion = "26.05";
 }