teardown csm

[HexaField]

Summary

🤖 Generated by Copilot at 9cf6df9

This pull request adds a method to remove the CSM plugin from mesh materials and calls it when an object is unmounted from the scene. This improves the memory management and performance of the CSM feature.

References

closes #insert number here

Explanation

🤖 Generated by Copilot at 9cf6df9

• Add a method to remove CSM plugin and defines from a mesh material (link)
• Call this method on each mesh child of an object when it is unmounted from the scene (link)

🤖 Generated by Copilot at 9cf6df9

teardownMaterial
cleans up shadow map plugin
leaves no trace in scene

QA Steps

List any additional steps required to QA the changes of this PR, as well as any supplemental images or videos.

Checklist

• If this PR is still a WIP, convert to a draft
• When this PR is ready, mark it as "Ready for review"
• ensure all checks pass
• Changes have been manually QA'd
• Changes reviewed by at least 2 approved reviewers