Dual-root backfill migration

Wave 7 dual-signs every new seal under both 40668… (legacy) and e5586… (Σ-2049 production). Wave 8 walks R2 historical artifacts and writes <key>.dual.json sidecars so prior chain entries are paired retroactively. Cron-driven, idempotent, non-destructive.

Legacy authority

40668c787c463ca5

flash_sync · 211a78f37783 · D-KaP / MONOTOLIC chain anchor

Σ-2049 production authority

e5586ef939094a8e

flash_sync · cd3715961fcf · MailMind + Quantum Tournament + Ultra Flash Sync

R2 prefix progress

Each card is one of the 5 prefixes the walker drains. Force-rerun with the button to re-seal regardless of existing sidecars.

Demo a dual seal

Type any JSON or text. Both authorities sign it. Verify round-trips.

Cron: task_backfill_walker @ 0 */6 * * * — drains up to 1,500 keys/cycle (5 prefixes × 3 pages × 100 keys). Manual: POST /api/sigma-2049/backfill?prefix=&batch=&force=. Status: GET /api/sigma-2049/backfill/status.