superstack-migratelisted

# superstack-migrate A migration is verified **data survival**, not applied DDL. "The migration ran" proves the layer below the claim (R1); the claim is "every row arrived intact and every reader still works." ## The method 1. **Dossier first — into the task file** (`.superstack/tasks/<slug>.md`; T2 work has earned one). Current shape → target shape; row counts *now* (they're the reconciliation baseline); every query/consumer touching the affected objects — grep the callers (R2: the readers you didn't find are the outage). 2. **Expand → migrate → contract, never one move.** Add the new alongside the old, move the data, switch the readers, and only then drop the old. Each step ends at a checkpoint with a **named verification query** — counts, checksums, sample diffs — and its expected result written *before* running (superstack-debug's probe discipline: a check whose outcome you can't predict is a coin flip). 3. **Rollback is tested, not asserted.** Before anything destructive: state the rollback and prove it on a copy **sized so the proof transfers** (see step 5 — a fraction you name, not a toy) — or verify the backup actually restores. Checker-must-fail applies to backups: an unrestored backup is an unverified check (superstack-experiential). 4. **The destructive step is a one-way door.** DROP, DELETE, the contract step: prepared as the exact command and **handed to the human** — never fired by this session (superstack-execute's pattern, same reason). Tier: T2 minimum; pr