Add a golden screenshot test

#[test]
#[ignore]
fn settings_phone_matches_golden() -> anyhow::Result<()> {
    let client = LiveTestClient::connect(control_port);
    client.wait_for_ready(15_000)?;
    client.simulate_resize(390, 844)?;
    client.wait_for_idle(2_000, false)?;
    client.tap_semantic_identifier("settings.open")?;

    client.compare_golden(
        "tests/goldens/settings-phone.png",
        Some(".artifacts/diffs/settings-phone.png"),
        GoldenOptions {
            channel_tolerance: 2,
            max_changed_percent: 0.2,
        },
    )?;
    Ok(())
}