Connect seam between LOD chunks

In its current status, boundaries between LOD chunks are not necessarily continuous.  Particularly in water, this artifact is very noticeable and needs to be addressed.

This can be seem especially clearly in the screenshot below:

<img width="1251" height="714" alt="Image" src="https://github.com/user-attachments/assets/4751a951-b513-44e5-832a-76e4f44a9034" />