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

features/apps/scripts/nomarchy-launch-tui

@@ -0,0 +1,5 @@
+#!/bin/bash
+
+# Launch the TUI command passed in as an argument in the default terminal with an org.nomarchy.COMMAND app id for styling.
+
+exec setsid uwsm-app -- xdg-terminal-exec --app-id=org.nomarchy.$(basename $1) -e "$1" "${@:2}"