Box3Blocks（神岛材质包）

This update mainly includes some detailed optimizations and the addition of minor features, as follows:

• "Superflat" World Preset Optimization
  When creating a new world, select "Superflat" mode, click "Customize," and choose our preset "Box3 Plain" to generate an initial terrain identical to that of Box3. The terrain consists of 8 layers: the first layer is grass, the second to seventh layers are dirt, and the eighth layer is stone.

• Y-Axis Offset Support for Box3 Structure Import
  To address the height mismatch issue that may occur when directly importing structures into Box3's existing 8-layer terrain, a Y-axis offset parameter has been added. Now, simply stand on the target ground, and you can generate structures parallel to the ground without any height difference.
  Command format:
  /box3import <fileName> <offsetY>
  This command adds an extra offset of the specified number of blocks along the Y-axis based on the current position (positive values for upward, negative for downward).

• Bug Fix
  Fixed an issue where bouncing blocks in Survival mode caused players to take damage upon falling onto them.