feat: persist independent provider attempt ledger

[christopherjnelson]

Summary

• add schema-v11 safe provider-attempt lifecycle records independent of committed turns
• preserve cancelled, timed-out, failed, retried, and post-validation provider work with bounded retention
• add SQLite archive v4 storage, idempotent lifecycle upserts, exact decimal reporting, and query support
• retain schema-v9/v10 compatibility and document the security and architecture boundaries

Validation

• pnpm validate
• pnpm test:e2e

Both commands were run successfully by the repository owner.