Milky Way panorama: ESO/S. Brunier. CC BY 4.0. https://www.eso.org/public/images/eso0932a/
License: https://creativecommons.org/licenses/by/4.0/
Changes: built from the 6000x3000 ESO original; compact point stars removed (replaced by the local median background) so catalog stars are not drawn twice; 4k, 2k levels area-averaged in linear light; converted to WebP. No 8k level: the source is 6000 px wide (< 8192) and is never upscaled. Reproduce with tools/build-milky-way-panorama.py.