exportSceneToGlb now calls snapLevelsToTruePositions() (the same clean stacked
presentation thumbnail capture uses) before snapshotting the scene, so the GLB
always reflects the stacked building regardless of the live levelMode
(exploded/solo) or an unsettled level lerp. Fixes baked GLBs where a level was
captured at a stray offset (e.g. ~ -100k Y), which inflated the bounding box and
made the model unframable / invisible in third-party glTF viewers.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
