feat: support time_zone for user registration context

authsession/internal/api/publichttp/handler.go

@@ -35,6 +35,7 @@ type confirmEmailCodeRequest struct {
 	ChallengeID     string `json:"challenge_id"`
 	Code            string `json:"code"`
 	ClientPublicKey string `json:"client_public_key"`
+	TimeZone        string `json:"time_zone"`
 }
 
 type confirmEmailCodeResponse struct {
@@ -142,6 +143,7 @@ func handleConfirmEmailCode(useCase ConfirmEmailCodeUseCase, timeout time.Durati
 			ChallengeID:     request.ChallengeID,
 			Code:            request.Code,
 			ClientPublicKey: request.ClientPublicKey,
+			TimeZone:        request.TimeZone,
 		})
 		if err != nil {
 			abortWithProjection(c, projectConfirmEmailCodeError(err))
@@ -195,6 +197,11 @@ func validateConfirmEmailCodeRequest(request *confirmEmailCodeRequest) error {
 		return errors.New("client_public_key must not be empty")
 	}
 
+	request.TimeZone = strings.TrimSpace(request.TimeZone)
+	if request.TimeZone == "" {
+		return errors.New("time_zone must not be empty")
+	}
+
 	return nil
 }