feat: add admin auth identity repair binding

backend/internal/handler/admin/admin_service_stub_test.go

@@ -18,6 +18,8 @@ type stubAdminService struct {
 	proxyCounts          []service.ProxyWithAccountCount
 	redeems              []service.RedeemCode
 	migrationReports     []service.AuthIdentityMigrationReport
+	boundAuthIdentity    *service.AdminBindAuthIdentityInput
+	boundAuthIdentityFor int64
 	createdAccounts      []*service.CreateAccountInput
 	createdProxies       []*service.CreateProxyInput
 	updatedProxyIDs      []int64
@@ -201,6 +203,52 @@ func (s *stubAdminService) GetAuthIdentityMigrationReportSummary(ctx context.Con
 	return summary, nil
 }
 
+func (s *stubAdminService) BindUserAuthIdentity(ctx context.Context, userID int64, input service.AdminBindAuthIdentityInput) (*service.AdminBoundAuthIdentity, error) {
+	s.boundAuthIdentityFor = userID
+	copied := input
+	if input.Metadata != nil {
+		copied.Metadata = map[string]any{}
+		for key, value := range input.Metadata {
+			copied.Metadata[key] = value
+		}
+	}
+	if input.Channel != nil {
+		channel := *input.Channel
+		if input.Channel.Metadata != nil {
+			channel.Metadata = map[string]any{}
+			for key, value := range input.Channel.Metadata {
+				channel.Metadata[key] = value
+			}
+		}
+		copied.Channel = &channel
+	}
+	s.boundAuthIdentity = &copied
+
+	now := time.Now().UTC()
+	result := &service.AdminBoundAuthIdentity{
+		UserID:          userID,
+		ProviderType:    input.ProviderType,
+		ProviderKey:     input.ProviderKey,
+		ProviderSubject: input.ProviderSubject,
+		VerifiedAt:      &now,
+		Issuer:          input.Issuer,
+		Metadata:        input.Metadata,
+		CreatedAt:       now,
+		UpdatedAt:       now,
+	}
+	if input.Channel != nil {
+		result.Channel = &service.AdminBoundAuthIdentityChannel{
+			Channel:        input.Channel.Channel,
+			ChannelAppID:   input.Channel.ChannelAppID,
+			ChannelSubject: input.Channel.ChannelSubject,
+			Metadata:       input.Channel.Metadata,
+			CreatedAt:      now,
+			UpdatedAt:      now,
+		}
+	}
+	return result, nil
+}
+
 func (s *stubAdminService) ListGroups(ctx context.Context, page, pageSize int, platform, status, search string, isExclusive *bool, sortBy, sortOrder string) ([]service.Group, int64, error) {
 	return s.groups, int64(len(s.groups)), nil
 }