src/checkout/components/
├── contact/              # Authentication & user display
├── shipping-address/     # Address selection & display
├── payment/              # Payment method & billing
└── AddressForm/          # Form utilities (existing)

import {
	SignInForm, // Email + password + forgot password
	SignedInUser, // Logged-in user display with sign out
	ResetPasswordForm, // New password form (reset callback)
	GuestContact, // Email input + create account checkbox
} from "@/checkout/components/contact";

import {
	AddressSelector, // Radio list for saved addresses
	AddressDisplay, // Read-only address card
} from "@/checkout/components/shipping-address";

// Also re-exported from AddressFormFields:
import { AddressFields, FormInput, FormSelect, FieldError } from "@/checkout/components/shipping-address";

import {
	PaymentMethodSelector, // Card/PayPal/iDEAL tabs
	BillingAddressSection, // Same-as-shipping toggle + form
	isCardDataValid, // Helper function
	type PaymentMethodType, // "card" | "paypal" | "ideal"
	type CardData, // { cardNumber, expiry, cvc, nameOnCard }
	type BillingAddressData, // { countryCode, formData, selectedAddressId? }
} from "@/checkout/components/payment";

// In InformationStep.tsx
import { SignInForm, SignedInUser, GuestContact } from "@/checkout/components/contact";
import { AddressSelector } from "@/checkout/components/shipping-address";

// Orchestrate based on auth state
{
	authenticated ? (
		<SignedInUser user={user} onSignOut={handleSignOut} />
	) : contactSection === "signIn" ? (
		<SignInForm onSuccess={handleSignInSuccess} />
	) : (
		<GuestContact email={email} onEmailChange={setEmail} />
	);
}