Add support for ГОСТ Р 34.10 digital signatures

- Implemented the GostKeyValue class for handling public key parameters in ГОСТ Р 34.10 digital signatures.
- Created the GostSignedXml class to manage XML signatures using ГОСТ 34.10, including methods for computing and checking signatures.
- Developed the GostSignedXmlImpl class to encapsulate the signature computation logic and public key retrieval.
- Added specific key value classes for ГОСТ Р 34.10-2001, ГОСТ Р 34.10-2012/256, and ГОСТ Р 34.10-2012/512 to support different signature algorithms.
- Ensured compatibility with existing XML signature standards while integrating ГОСТ cryptography.

docs/task-packs/authoring-guide.md

@@ -62,6 +62,7 @@ stella pack init --name sbom-remediation
 ### 3.4 Configure approvals
 
 - Add `spec.approvals` entries for each required review.
+- Capture the metadata Authority enforces: `runId`, `gateId`, and `planHash` should be documented so approvers can pass them through `stella pack approve --pack-run-id/--pack-gate-id/--pack-plan-hash` (see `docs/task-packs/runbook.md#4-approvals-workflow`).
 - Provide informative `reasonTemplate` with placeholders.
 - Set `expiresAfter` to match operational policy (e.g., 4 h for security reviews).
 - Document fallback contacts in `docs/runbook.md`.
@@ -205,4 +206,3 @@ Registry verifies signature, stores provenance, and updates index.
 ---
 
 *Last updated: 2025-10-27 (Sprint 43).* 
-