vanilla_world_check.py (used by the light harness) defaulted to port 25671, so two parity runs on one machine failed with 'FAILED TO BIND TO PORT'. It now picks a free port unless --port is given. The save round trip, datafix and upgrade_world tools derived their port from the pid or a random number; they ask the OS for a free one like test_dedicated_server_parity does.
Fixes#461
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
datafix_scene_12.py builds one scene for 1.8 to 1.12 from per-era tables (blocks, entity ids and merged types, riding, equipment, potions, items probed on the server, achievements by command instead of advancements).
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
tools/datafix_scene_12.py builds it in 1.12 command syntax: the whole block id/data space, block entities, items, entities, player, scoreboard, advancements, maps and statistics (real ones from a bot, plus a few hand-written fixtures).
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>