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-walker

@@ -0,0 +1,15 @@
+#!/bin/bash
+
+# Launch the Walker application launcher while ensuring that it's data provider (called elephant) is running first.
+
+# Ensure elephant is running before launching walker
+if ! pgrep -x elephant > /dev/null; then
+  setsid uwsm-app -- elephant &
+fi
+
+# Ensure walker service is running
+if ! pgrep -f "walker --gapplication-service" > /dev/null; then
+  setsid uwsm-app -- walker --gapplication-service &
+fi
+
+exec walker --width 644 --maxheight 300 --minheight 300 "$@"