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-tui-install

@@ -0,0 +1,59 @@
+#!/bin/bash
+
+set -e
+
+if (( $# != 4 )); then
+  echo -e "\e[32mLet's create a TUI shortcut you can start with the app launcher.\n\e[0m"
+  APP_NAME=$(gum input --prompt "Name> " --placeholder "My TUI")
+  APP_EXEC=$(gum input --prompt "Launch Command> " --placeholder "lazydocker or bash -c 'dust; read -n 1 -s'")
+  WINDOW_STYLE=$(gum choose --header "Window style" float tile)
+  ICON_URL=$(gum input --prompt "Icon URL> " --placeholder "See https://dashboardicons.com (must use PNG or SVG!)")
+else
+  APP_NAME="$1"
+  APP_EXEC="$2"
+  WINDOW_STYLE="$3"
+  ICON_URL="$4"
+fi
+
+if [[ -z $APP_NAME || -z $APP_EXEC || -z $ICON_URL ]]; then
+  echo "You must set app name, app command, and icon URL!"
+  exit 1
+fi
+
+ICON_DIR="$HOME/.local/share/applications/icons"
+DESKTOP_FILE="$HOME/.local/share/applications/$APP_NAME.desktop"
+
+if [[ ! $ICON_URL =~ ^https?:// ]] && [[ -f $ICON_URL ]]; then
+  ICON_PATH="$ICON_URL"
+else
+  ICON_PATH="$ICON_DIR/$APP_NAME.png"
+  mkdir -p "$ICON_DIR"
+  if ! curl -sL -o "$ICON_PATH" "$ICON_URL"; then
+    echo "Error: Failed to download icon."
+    exit 1
+  fi
+fi
+
+if [[ $WINDOW_STYLE == "float" ]]; then
+  APP_CLASS="TUI.float"
+else
+  APP_CLASS="TUI.tile"
+fi
+
+cat >"$DESKTOP_FILE" <<EOF
+[Desktop Entry]
+Version=1.0
+Name=$APP_NAME
+Comment=$APP_NAME
+Exec=xdg-terminal-exec --app-id=$APP_CLASS -e $APP_EXEC
+Terminal=false
+Type=Application
+Icon=$ICON_PATH
+StartupNotify=true
+EOF
+
+chmod +x "$DESKTOP_FILE"
+
+if (( $# != 4 )); then
+  echo -e "You can now find $APP_NAME using the app launcher (SUPER + SPACE)\n"
+fi