Islands of Stability, orbits: pre-registration (r2)

This deposit fixes, before it is run, the corrected version of a model test of where proposition 3 of Islands of Stability (islandsofstability.com) stops applying. Its first version, r1 (10.5281/zenodo.23066015), ran once and did not measure what it was built to measure: its neighbourhood, a square around the island, did not contain the island, whose outermost unbroken curve reaches 2.15 in momentum where the square stopped at 1.8. The author recorded r1 as invalid, and it stays on record beside this one. r2 changes three things. The neighbourhood is measured from the island's full edge and contains every regular orbit of the island and the chain of smaller islands beyond it. The undisturbed arm is a positive control: theory is certain that frictionless orbits stick to an island's edge, so if that arm does not show memory the test is void and no verdict is entered. And every stay of the disturbed arm starts at the island's centre, so that all stays have the same depth, as proposition 3 requires. Only the disturbed arm decides the verdict. Nothing in this deposit has been run. The test's random seeds are the first 16 hexadecimal digits of the SHA-256 of this record's DOI, so they could not have been chosen after seeing results. r2/run_test_r2.py requires the DOI and refuses to run unless every frozen file matches r2/lock.json. Contents of bundle.zip (SHA256SUMS lists a hash for every file): r2/PREREGISTRATION.md: the frozen document (r2), also uploaded on its own; r2/PREREGISTRATION-draft.md is the draft, kept for the record. r2/lock.json and r2/freeze_r2.py: the SHA-256 of every frozen file, and the check (python r2/freeze_r2.py --verify). stdmap.py and sticky.py: r1's map and stay statistics, reused unchanged. r2/design_r2.py and r2/design.json: the island's measured edge and the neighbourhood, from the deterministic map. r2/sticky_r2.py and r2/run_test_r2.py: the changes and the runner (python r2/run_test_r2.py --doi ). r2/tests/: unit tests (python -m pytest -q r2/tests). results/r1-NOTES.md, island_extent.py and results/r1-island-extent.txt: r1's run note and the diagnostic that found its flaw. Related: pre-registration r1 of this test (10.5281/zenodo.23066015) and the pre-registration of the site's first instrument, snapshot 1 of the Map (10.5281/zenodo.22982434). Drafted with Claude (Anthropic), an AI assistant; every decision recorded in the document was made by the author.