🌐 Safe iFrame Connectivity Test
1. https://example.com
Expected: Simple HTML placeholder.
2. https://httpbin.org/html
Expected: Sample HTML returned by httpbin.
3. http://neverssl.com
Expected: HTTP-only page to test redirect/captive portal.
4. https://icanhazdadjoke.com/embedded
Expected: A random (and hilarious) joke appears.
5. http://open-notify.org/Open-Notify-API/
Expected: Text page showing space API links.
6. http://httpforever.com
Expected: Simple HTTP test page for captive networks.