Add settings page and store with UI customization options

- Implement SettingsView with appearance, data, notifications, and
advanced tabs - Add settings store (Pinia) for theme, navigation,
notifications, and app config - Integrate settings store into HomeView
and BottomNav for theme and navigation mode - Add room management modal
and store methods for adding/removing rooms - Update
SensorManagementView with room management button and modal - Support
exporting/importing settings and resetting to defaults - Enable dark
mode via Tailwind config

tailwind.config.js

@@ -4,6 +4,7 @@ export default {
     "./index.html",
     "./src/**/*.{vue,js,ts,jsx,tsx}",
   ],
+  darkMode: 'class',
   theme: {
     extend: {},
   },