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/lozengeFaceted.svg

@@ -0,0 +1,11 @@
+<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="lozengeFaceted">
+    <polygon points="100 55 130 100 100 145 70 100"/>
+    <g fill="#000" stroke="none">
+      <polygon points="100 100 130 100 100 55" opacity=".2"/>
+      <polygon points="100 100 70 100 100 145" opacity=".2"/>
+      <polygon points="100 100 130 100 100 145" opacity=".3"/>
+    </g>
+  </g>
+</svg>