feat(payment): expand Stripe methods and checkout handoff

src/lib/auth/checkout_handoff.ts

@@ -0,0 +1,18 @@
+import type {
+  CheckoutHandoffCreateResponse,
+  CheckoutIntent,
+} from "@/data/schemas/auth";
+import { getAuthRepository } from "@/data/repositories/auth_repository";
+import type { Result } from "@/utils/result";
+
+export function createCheckoutHandoff(
+  checkoutIntent: CheckoutIntent,
+): Promise<Result<CheckoutHandoffCreateResponse>> {
+  return getAuthRepository().createCheckoutHandoff(checkoutIntent);
+}
+
+export function consumeCheckoutHandoff(
+  handoffToken: string,
+): Promise<Result<CheckoutIntent>> {
+  return getAuthRepository().consumeCheckoutHandoff(handoffToken);
+}