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-or-focus-tui

@@ -0,0 +1,9 @@
+#!/bin/bash
+
+# Launch or focus on a given TUI identified by the passed in as the command.
+# Use by commands like nomarchy-launch-wifi to ensure there is only one wifi configuration screen open.
+
+APP_ID="org.nomarchy.$(basename "$1")"
+LAUNCH_COMMAND="nomarchy-launch-tui $@"
+
+exec nomarchy-launch-or-focus "$APP_ID" "$LAUNCH_COMMAND"