Leetcode 3391. Design a 3D Binary Matrix with Efficient Layer Tracking

Design a mutable 3D binary matrix that supports point updates and layer- or axis-aligned queries (e.g., count of 1s in a given 2D layer or sub-block) while keeping operations efficient. The core challenge is maintaining and updating aggregate counts for entire layers/planes under frequent updates so queries run much faster than scanning the whole 3D array.