Implement Standalone Android App via Flutter WebView

- Configured `vite.config.ts` for relative base path support.
- Initialized `mobile_app` Flutter project with `webview_flutter`.
- Added `assets/www` to Flutter assets configuration.
- Implemented `mobile_app/lib/main.dart` with WebView and Bridge API integration (Water Level Slider).
- Updated `.gitignore` for Flutter artifacts.
- Successfully built APK artifacts.

Co-authored-by: kliffdafunkfacekilla-arch <239708976+kliffdafunkfacekilla-arch@users.noreply.github.com>

mobile_app/assets/www/charges/crossCalvary.svg

@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" fill="#d7374a" stroke="#000" viewBox="50 50 200 200"><metadata author="Azgaar" license="https://creativecommons.org/publicdomain/zero/1.0"/><g id="crossCalvary" stroke-width=".5"><path d="m 95,55 h 10 v 15 h 20 v 10 h -20 v 40 h 3 v 10 h 10 v 10 h 17 v 10 H 65 v -10 h 17 v -10 h 10 v -10 h 3 V 80 H 75 V 70 h 20 z"/></g></svg>