Variable dropUnusedTextureConst

dropUnusedTexture: Fix = ...

Auto-fix for TEXTURE_UNUSED — destroys a SceneTexture that no SceneMaterial binds. The fix checks live material texture slots by object identity before destroying; this lets it clean up models whose numMaterials counter was left stale by a replaced same-id texture pointer.

Idempotent: returns {fixed: false} when the texture is already destroyed or absent.