refactor: implement component-based architecture for enhanced maintainability

- Reorganize directory structure into core/, features/, and themes/
- Colocate application Nix logic, configs, scripts, and theme overrides
- Implement 'Inversion of Control' for theming: apps now pull theme-specific layouts
- Update flake.nix and shared library paths to match the new structure
- Document the new Feature-Centric architecture in README.md

core/system/vm-guest.nix

@@ -0,0 +1,17 @@
+{ lib, ... }:
+
+{
+  # Shared VM configuration
+  virtualisation.vmVariant = {
+    virtualisation.graphics = true;
+    virtualisation.qemu.options = [ "-device virtio-vga" ];
+  };
+
+  # Dummy hardware config for VM
+  fileSystems."/" = { device = "/dev/disk/by-label/nixos"; };
+  boot.loader.grub.device = "/dev/vda";
+  boot.initrd.availableKernelModules = [ "virtio_pci" "virtio_blk" "virtio_gpu" "virtio_net" "virtio_mmio" ];
+  
+  # Force early KMS for Plymouth
+  boot.initrd.kernelModules = [ "virtio_gpu" ];
+}