HostedCheckoutScreen
fun HostedCheckoutScreen(checkoutUrl: String, matchReturn: (String) -> HostedReturnOutcome?, onResult: (HostedReturnOutcome) -> Unit, modifier: Modifier = Modifier)
Renders one hosted gateway's checkout page and watches every navigation for the return-URL pattern. docs: https://github.com/KevinnZou/compose-webview-multiplatform — state.lastLoadedUrl is the interception point; the moment matchReturn recognizes a redirect as terminal, onResult fires exactly once (the reported guard survives re-navigation inside the same page load).
SECURITY: SSL/certificate errors fail closed via sslFailClosedWebViewParams — its Android actual cancels the load and reports HostedReturnOutcome.Failure through onResult; never call handler.proceed() — a flaky regional cert is not a reason to bypass certificate validation on a checkout page. See that function's KDoc for the iOS parity gap.