클라이언트 대시보드 통계 실지표 연동 및 백엔드 API 구현

backend/internal/domain/models.go

@@ -25,6 +25,8 @@ type AuditRepository interface {
 	Create(log *AuditLog) error
 	FindPage(ctx context.Context, limit int, cursor *AuditCursor) ([]AuditLog, error)
 	FindByUserAndEvents(ctx context.Context, userID string, eventTypes []string, limit int) ([]AuditLog, error)
+	CountFailuresSince(ctx context.Context, since time.Time, tenantID string) (int64, error)
+	CountActiveSessionsSince(ctx context.Context, since time.Time, tenantID string) (int64, error)
 	Ping(ctx context.Context) error
 }