{
  "number": 409,
  "date": "2026-09-24",
  "title": "Fixed Mirror-corner test of the Shem loop translation",
  "question": "Test both existing17K source-corner exchanges and the fixed−500 shift without changing their constants.",
  "authorization": "User authorized next10 bounded steps C404–C413; 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."
}