security(protocol): add issuer key transparency and rotation history

[enliven17]

Summary

Make institutional issuer identity and key history independently auditable while detecting stale or equivocated metadata.

Motivation

Harpocrates needs this capability to become a production-grade, interoperable evidence protocol while preserving privacy, deterministic verification, and safe failure behavior. The implementation must reuse existing metadata, manifest, ZK, backend, frontend, and Soroban boundaries instead of creating parallel truth sources.

Scope

• Define a canonical signed issuer metadata manifest with organization identity hash, active keys, validity, policy, and successor/predecessor links.
• Maintain append-only activation, rotation, compromise, and retirement records.
• Publish signed directory checkpoints and deterministic consistency verification.
• Add client/backend caching with freshness rules and fail-closed behavior for high-assurance seals.
• Expose history and verification tooling without publishing private organization data.

Acceptance criteria

• Tests detect split views, rollback, stale checkpoints, broken rotation links, conflicting manifests, and compromised keys.
• Directory rebuild from authoritative events is deterministic.
• Key rotation does not invalidate historical signatures incorrectly.
• Operational docs cover onboarding, compromise response, checkpoint signing, and recovery.
• Existing lint, type checks, tests, builds, contract checks, and privacy guarantees remain green.

Engineering expectations

Use versioned canonical encodings, explicit error/status types, bounded resource consumption, idempotent operations, and privacy-safe observability. Schema, contract, circuit, or artifact changes require migration and compatibility analysis. Cryptographic changes require stable vectors and a written threat model.

Out of scope

Live production deployment, real credentials or sensitive media, unrelated visual redesigns, and broad dependency upgrades not required by this objective.

Definition of done

A maintainer can reproduce success and adversarial failure paths locally, understand the trust and privacy boundaries, operate the feature safely, and roll it back without undocumented state repair.

[Elizabeth-dev270]

@Elizabeth-dev270 has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I would like to fix this quickly

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Elizabeth-dev270 to this issue.

[drips-wave]

Congratulations, @Elizabeth-dev270! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on July 30, 2026.

🧑‍💻 @Elizabeth-dev270: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

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