feat: publish immutable recovery state ledgers

[Pigbibi]

Summary

• derive the minimal state ledger only from a complete fresh verify-only result
• add an explicit GCS adapter that uses create-only generation preconditions
• retain default local JSON output without cloud, deployment, broker, or order side effects

Verification

• targeted state-ledger publisher and consumer tests
• Ruff checks

The state-ledger URI remains unset; this PR does not enable a recovery or modify a runtime target.