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/libs/umami.js

@@ -0,0 +1,36 @@
+(window => {
+  const noTrack = window.localStorage.getItem("noTrack");
+
+  const {
+    screen: {width, height},
+    navigator: {language},
+    location: {hostname, pathname, search},
+    document: {referrer}
+  } = window;
+
+  const website = "4f6fd0ae-646a-4946-a9da-7aad63284e48";
+  const root = "https://fmg-stats.herokuapp.com";
+  const screen = `${width}x${height}`;
+  const url = `${pathname}${search}`;
+
+  const post = (url, data) => {
+    const req = new XMLHttpRequest();
+    req.open("POST", url, true);
+    req.setRequestHeader("Content-Type", "application/json");
+    req.send(JSON.stringify(data));
+  };
+
+  const collect = (type, params) => {
+    if (noTrack) return;
+
+    const payload = {website, hostname, screen, language, cache: false};
+    Object.keys(params).forEach(key => {
+      payload[key] = params[key];
+    });
+
+    post(`${root}/api/collect`, {type, payload});
+  };
+
+  collect("pageview", {url, referrer});
+  window.track = (event_type = "reach", event_value = "") => collect("event", {event_type, event_value, url});
+})(window);