feat(ECR-015): RedemptionCode 兑换码并 Closed

批次生成/作废、C 端兑码延长会员；admin-h5 /codes。
Loop continuous。Next：ECR-016 UserIntelligence。

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/api/internal/service/membership/service.go

@@ -4,6 +4,7 @@ package membership
 import (
 	"context"
 	"errors"
+	"strings"
 	"time"
 
 	"github.com/google/uuid"
@@ -58,6 +59,15 @@ func (s *Service) CreateOrder(ctx context.Context, userID uuid.UUID, in CreateOr
 	return s.Reports.CreateOrder(ctx, userID, in.Kind, plan, in.ReportID, amount)
 }
 
+// Redeem applies a redemption code for the current registered user.
+func (s *Service) Redeem(ctx context.Context, userID uuid.UUID, code string) (string, error) {
+	code = strings.TrimSpace(code)
+	if code == "" {
+		return "", errors.New("code required")
+	}
+	return s.Reports.RedeemCode(ctx, userID, code)
+}
+
 // PayMock completes mock payment.
 func (s *Service) PayMock(ctx context.Context, userID, orderID uuid.UUID) error {
 	return s.Reports.PayMock(ctx, userID, orderID)