{
  "number": 420,
  "date": "2026-09-24",
  "title": "Fixed-pivot harmonic endpoint tests of the five 2K stations",
  "question": "Apply the four specified gap multipliers at five fixed upper stations and test exact outputs and E intermediates.",
  "authorization": "User authorized next10 bounded steps C414–C423; next question reassessed after each completed result.",
  "scope": "Mirror/529; regular Gears Noah/Shem/Flood only; SP companion local. Fixed source inputs, no canonical/graph changes."
}