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>

vite.config.ts

@@ -1,9 +1,21 @@
 export default {
     root: './src',
-    base: process.env.NETLIFY ? '/' : '/Fantasy-Map-Generator/',
+    base: './',
     build: {
         outDir: '../dist',
-        assetsDir: './',
+        assetsDir: 'assets', // Cleaner
+        rollupOptions: {
+            input: {
+                main: './src/index.html',
+                engine: './src/engine/engine.html',
+            },
+        },
     },
     publicDir: '../public',
-}
+    server: {
+        headers: {
+            'Cross-Origin-Opener-Policy': 'same-origin',
+            'Cross-Origin-Embedder-Policy': 'require-corp',
+        },
+    },
+}