Add subcription feature 4

frontend/src/components/domain/auth/PaymentStep.tsx

@@ -264,7 +264,7 @@ export const PaymentStep: React.FC<PaymentStepProps> = ({
         // Store payment method ID for use after 3DS completion
         setPendingPaymentMethodId(paymentMethod.id);
 
-        // Update paymentSetup state with customer_id for redirect recovery
+        // Update paymentSetup state with customer_id and trial_period_days for redirect recovery
         updateRegistrationState({
           paymentSetup: {
             success: false,
@@ -272,6 +272,7 @@ export const PaymentStep: React.FC<PaymentStepProps> = ({
             subscriptionId: '',
             paymentMethodId: paymentMethod.id,
             planId: registrationState.subscription.planId,
+            trialPeriodDays: paymentSetupResult.trial_period_days ?? (registrationState.subscription.useTrial ? 90 : 0),
           },
         });
 
@@ -353,6 +354,7 @@ export const PaymentStep: React.FC<PaymentStepProps> = ({
         : setupIntent.payment_method?.id || pendingPaymentMethodId;
 
       // Complete registration with verified SetupIntent using React Query mutation
+      // Send coupon_code to backend for trial period calculation
       const verificationResult = await completeRegistrationMutation.mutateAsync({
         setup_intent_id: setupIntentId || '',
         user_data: {
@@ -363,6 +365,9 @@ export const PaymentStep: React.FC<PaymentStepProps> = ({
           billing_cycle: registrationState.subscription.billingInterval,
           payment_method_id: confirmedPaymentMethodId || pendingPaymentMethodId,
           coupon_code: registrationState.subscription.couponCode,
+          // Pass customer_id for reference
+          customer_id: registrationState.paymentSetup?.customerId || '',
+          // Remove trial_period_days - backend will calculate from coupon_code
         },
       });