HostedCheckoutHost
fun HostedCheckoutHost(relay: HostedCheckoutRelay, configs: List<HostedGatewayConfig>, modifier: Modifier = Modifier)
Subscribes to HostedCheckoutRelay.requests and renders HostedCheckoutScreen for whichever hosted gateway is currently mid-checkout; reports the outcome back through the same relay so HostedWebViewGateway.pay resumes. configs is the app's assembled list of HostedGatewayConfig.