[Bug] Hiding URL bar on scroll doesn't work well with Flutter web apps

Describe the bug

It seems that DDG considers every website scrollable and hides the URL bar. This introduces an empty bar below the page. If I go to https://example.com and scroll down, the web page constantly rerenders to fill the created empty space. However, Flutter web apps do not re-render, which makes the user experience for web apps with bottom navigation bars pretty bad.

How to Reproduce

1. Go to https://wonderous.app/web
2. Open any of the wonders
3. Scroll down

The URL bar disappears and an empty space appears below the bottom navigation bar. (The white bar at the top of the screenshot is the task bar of my phone and gets hidden during screenshots.)

Expected behavior

Not sure what the desired behavior is here. I feel like pages should not be scrollable if they don't actually extend beyond the screen.

Environment

- DDG App Version: 5.201.1
- Device: Pixel 8
- OS: Android 14

Reproduce the problem at wonderous.app/web in DDG App 5.201.1 on Android 14 using the reported scroll steps, then trace the app's URL-bar and page-scroll handling. Done means the URL bar behavior no longer leaves an empty space beneath Flutter web apps with bottom navigation bars, with the expected behavior agreed first.