Create a complete Stripe payment integration for a mobile app that includes:

— Set up Stripe Mobile SDK for [Android/Kotlin/iOS/Swift] with proper configuration
— Implement client-side card tokenization using Stripe's secure elements
— Create custom payment sheet UI that matches app design
— Handle 3D Secure authentication flows
— Process payments via PaymentIntent API with error handling
— Manage Google Pay/Apple Pay integration
— Implement payment status tracking and receipt handling

Scaffold(
    topBar = { TopAppBar(title = { Text("Hello") }) },
    floatingActionButton = { FloatingActionButton(onClick = { }) { Icon(Icons.Default.Add, null) } }
) {
    // content
}

val isFormValid by remember {
    derivedStateOf { email.isNotEmpty() && password.length >= 8 }
}

val name by rememberSaveable { mutableStateOf("") }

LaunchedEffect(userId) {
    viewModel.loadUser(userId)
}

fun Modifier.defaultPadding() = padding(16.dp)