feat: support time_zone for user registration context

authsession/internal/service/confirmemailcode/service.go

@@ -19,9 +19,10 @@ import (
 )
 
 const (
-	revokeReasonConfirmRace common.RevokeReasonCode = "confirm_race_repair"
-	revokeActorTypeService  common.RevokeActorType  = "service"
-	revokeActorIDService                            = "confirmemailcode"
+	revokeReasonConfirmRace  common.RevokeReasonCode = "confirm_race_repair"
+	revokeActorTypeService   common.RevokeActorType  = "service"
+	revokeActorIDService                             = "confirmemailcode"
+	defaultPreferredLanguage                         = "en"
 )
 
 // Input describes one public confirm-email-code request.
@@ -35,6 +36,11 @@ type Input struct {
 	// ClientPublicKey is the base64-encoded raw 32-byte Ed25519 public key that
 	// should be registered for the created device session.
 	ClientPublicKey string
+
+	// TimeZone is the client-selected IANA time zone name that should be
+	// forwarded as create-only registration context when the user does not yet
+	// exist.
+	TimeZone string
 }
 
 // Result describes one public confirm-email-code response.
@@ -192,6 +198,10 @@ func (s *Service) Execute(ctx context.Context, input Input) (result Result, err
 	if err != nil {
 		return Result{}, err
 	}
+	timeZone, err := shared.ParseTimeZone(input.TimeZone)
+	if err != nil {
+		return Result{}, err
+	}
 
 	for attempt := 0; attempt < shared.MaxCompareAndSwapRetries; attempt++ {
 		current, err := s.challengeStore.Get(ctx, challengeID)
@@ -236,7 +246,13 @@ func (s *Service) Execute(ctx context.Context, input Input) (result Result, err
 			return Result{}, shared.InvalidCode()
 		}
 
-		ensureUserResult, err := s.userDirectory.EnsureUserByEmail(ctx, current.Email)
+		ensureUserResult, err := s.userDirectory.EnsureUserByEmail(ctx, ports.EnsureUserInput{
+			Email: current.Email,
+			RegistrationContext: &ports.RegistrationContext{
+				PreferredLanguage: defaultPreferredLanguage,
+				TimeZone:          timeZone,
+			},
+		})
 		if err != nil {
 			return Result{}, shared.ServiceUnavailable(err)
 		}