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/spec.md

@@ -131,7 +131,7 @@ spec:
 | `metadata` | Human-facing metadata; used for registry listings and RBAC hints. | `name` (DNS-1123), `version` (SemVer), `description` ≤ 2048 chars. |
 | `spec.inputs` | Declarative inputs validated at plan time. | Must include type; custom schema optional but recommended. |
 | `spec.secrets` | Secrets requested at runtime; never stored in pack bundle. | Each secret references Authority scope; CLI prompts or injects from profiles. |
-| `spec.approvals` | Named approval gates with required grants and TTL. | ID unique per pack; `grants` map to Authority roles. |
+| `spec.approvals` | Named approval gates with required grants and TTL. | ID unique per pack; `grants` map to Authority roles. Approval metadata (`runId`, `gateId`, `planHash`) feeds Authority’s `pack_run_id`/`pack_gate_id`/`pack_plan_hash` parameters (see `docs/task-packs/runbook.md#4-approvals-workflow`). |
 | `spec.steps` | Execution graph; each step is `run`, `gate`, `parallel`, or `map`. | Steps must declare deterministic `uses` module and `id`. |
 | `spec.outputs` | Declared artifacts for downstream automation. | `type` can be `file`, `object`, or `url`; path/expression required. |
 | `success` / `failure` | Messages + retry policy. | `failure.retries.maxAttempts` + `backoffSeconds` default to 0. |
@@ -246,4 +246,3 @@ CLI enforces compatibility: running pack with unsupported features yields `ERR_P
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 *Last updated: 2025-10-27 (Sprint 43).* 
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