- docs/datapack-upgrade.md: how to run `horizon-port-pack
upgrade-datapack`, every rewrite and how it is checked, and what is not
rewritten; linked from docs/README.md and the command's help.
- tools/datapack_upgrade_rosetta.py writes vanilla 26.2's own worldgen out
as a pack, upgrades it and compares it with vanilla 26.3's file by file:
registries whose format changed and whose content did not must come out
identical.
- tools/datapack_upgrade_fidelity.py starts vanilla's 26.2 and 26.3
dedicated servers on the same seed, the first with a pack and the second
with its upgrade, force loads the same chunks and compares the saved
blocks; without packs it measures what 26.3 itself changed.
Both need the 26.2 server jar the player downloaded; nothing is fetched.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
