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/scripts/utils/nomarchy-npx-install

@@ -0,0 +1,24 @@
+#!/bin/bash
+
+# Install an npx wrapper for a given npm package.
+# Usage: nomarchy-npx-install <package> [command-name]
+#
+# If command-name is omitted, it defaults to the package name.
+# Example: nomarchy-npx-install opencode-ai opencode
+
+if [[ -z $1 ]]; then
+  echo "Usage: nomarchy-npx-install <package> [command-name]"
+  exit 1
+fi
+
+package=$1
+command=${2:-$1}
+
+mkdir -p "$HOME/.local/bin"
+
+cat > "$HOME/.local/bin/$command" <<EOF
+#!/bin/bash
+exec npx --yes $package "\$@"
+EOF
+
+chmod +x "$HOME/.local/bin/$command"