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-show-logo

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+# Display the Nomarchy logo in the terminal using green color.
+# Used by various presentation scripts to show branding.
+
+clear
+echo -e "\033[32m"
+cat < ~/.config/nomarchy/branding/logo.txt
+echo -e "\033[0m"