State Production: protocol-migrate history Command

[aristidesstaffieri]

Summary

Implement the history migration subcommand that backfills protocol state changes within the retention window, converging with live ingestion via the shared history CAS cursor.

Scope

• CLI: ./wallet-backend protocol-migrate history --protocol-id SEP50 SEP41
• Phase 1 — Validate: Verify protocol exists, classification_status = 'success'. Set history_migration_status = 'in_progress'. Read oldest_ledger_cursor. Initialize protocol_{ID}_history_cursor = oldest_ledger_cursor - 1.
• Phase 2 — Process batches to tip (loop): Read latest_ledger_cursor as target. Split [cursor+1, target] into batches. Process batches sequentially (parallel comes in Task 6). Each batch commit: CAS-advance history cursor + write state changes. On CAS fail → handoff detected, exit loop. After all batches: re-read latest cursor, repeat if more ledgers; if caught up, block on RPC for next ledger (~5s).
• Phase 3 — Complete: Verify cursor at or past attempted ledger. Set history_migration_status = 'success'. Clean up.
• Error handling: set history_migration_status = 'failed', log error. On retry: resume from cursor + 1.
• All processed ledgers are within retention — no "process but discard" logic needed.

Dependencies

• State Production: CompareAndSwap Method on IngestStoreModel #512 (CompareAndSwap Method on IngestStoreModel)
• State Production: Protocol State Processor Registry #513 (Protocol State Processor Interface)

Reference

docs/feature-design/data-migrations.md (State Production section, line 619+)