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/plymouth/nomarchy.plymouth

@@ -0,0 +1,11 @@
+[Plymouth Theme]
+Name=Nomarchy
+Description=Omarchy splash screen.
+ModuleName=script
+
+[script]
+ImageDir=/usr/share/plymouth/themes/nomarchy
+ScriptFile=/usr/share/plymouth/themes/nomarchy/nomarchy.script
+ConsoleLogBackgroundColor=0x1a1b26
+MonospaceFont=Cantarell 11
+Font=Cantarell 11