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

themes/engine/scripts/nomarchy-theme-set-keyboard-asus-rog

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+ASUSCTL_THEME=~/.config/nomarchy/current/theme/keyboard.rgb
+
+if nomarchy-cmd-present asusctl; then
+  asusctl aura effect static -c $(sed 's/^#//' $ASUSCTL_THEME)
+fi