Promote the J1, J2 and J3 counters that were identical in all 55 measured
iterations of the 11 master runs from 2026-10-03 to 2026-10-04 to
journey-baselines.json, and check them in the Performance journeys job
(still warn-only), in one step together with #1828's two validated J1
entries. None of the new ones has Principle 3 evidence, so each carries a
"guard only, not validated" note that the checker prints with a failure.
A performance-tools test keeps the job's --only list equal to the journey
entries. Number formatting uses three decimals, the precision of the
layout-shift scores.
J2 renderer.layoutShiftScore is 0.233, not the window's 0.222: every
master run from #1814 (page Back buttons in the header) on reads 0.233.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>