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/home/fonts.nix

@@ -0,0 +1,8 @@
+{ lib, ... }:
+
+{
+  config = {
+    fonts.fontconfig.enable = lib.mkDefault true;
+    xdg.dataFile."fonts/nomarchy.ttf".source = lib.mkDefault ../../config/nomarchy.ttf;
+  };
+}