CT volume view (lib/ctvolume.js, lib/ctsource.js): a cube of the raw X-ray scan around a picked papyrus point (256 voxels, 128 on phones) as a Data3DTexture, raymarched MIP clipped to an oriented slab that starts square to the surface; own canvas beside the scroll, render on demand; panel group (Pick a point, Show volume) and floating panel with slab, tilt, window/level, size and detail controls; Settings, unrollView.ct.volume API and actions, ?ctvol URLs, scanGeom and scanPick hooks in app.js, glossary (MIP, slab, CT volume, raymarching), docs
