needsRebalancing method
Determines if tree needs rebalancing based on compression metrics
Decision Formula: Rebalance when: compressionRatio < 0.1 (tree is under-compressed) OR sparsityRatio > 0.7 (tree is too sparse)
Implementation
bool needsRebalancing() {
final stats = getStats();
final double compressionRatio = stats['compressionRatio'] as double;
final double sparsityRatio = stats['sparsityRatio'] as double;
return compressionRatio < 0.1 || sparsityRatio > 0.7;
}