S00-020: Verify pinned Linux XMPP toolchain restoration

Changes: Refresh the environment-access result and document S00-020 restoration, accepted prerequisites and independent QA handoff; preserve probe code and parent dependency graph.
Validation: verify.py passed official HTTPS vendor checksum, Node 24.21.0/npm 11.19.0, fresh-cache strict npm ci and Stanza import. Separate artifact/input/version/strict-setting assertions and tasks.py validate passed. No browser/WSS or product readiness check performed.

Task: S00-020
Agent: auto-ci-cd-2a0186c54ce9
Role: ci-cd
Action: claim
Status: review

Task title: Restore access to the pinned Linux XMPP experiment toolchain

planning/TASK_MATRIX.md

@@ -1,6 +1,6 @@
 # Матрица задач
 
-Generated; state revision **83**. Canonical status: state/tasks.json.
+Generated; state revision **85**. Canonical status: state/tasks.json.
 
 | ID | Этап | Оператор | Reviewer | Статус | Owner | Зависимости | Задача |
 | --- | --- | --- | --- | --- | --- | --- | --- |
@@ -22,7 +22,7 @@ Generated; state revision **83**. Canonical status: state/tasks.json.
 | [S00-017](tasks/S00-017.md) | S00 | protocol | security | done | auto-protocol-599343cd9e3f | S00-001, S00-002 | Establish fail-closed SCRAM server-final validation |
 | [S00-018](tasks/S00-018.md) | S00 | protocol | security | done | auto-protocol-89fe6563092c | S00-001, S00-002, S00-017 | Validate bounded standalone XML ingress for the XMPP candidate |
 | [S00-019](tasks/S00-019.md) | S00 | crypto | security | done | auto-crypto-c68801170fa4 | S00-001, S00-002, S00-017, S00-018 | Validate browser-compatible SCRAM-SHA-512 through a public mechanism API |
-| [S00-020](tasks/S00-020.md) | S00 | ci-cd | qa | todo |  | S00-001, S00-002, S00-017, S00-018, S00-019, S00-024 | Restore access to the pinned Linux XMPP experiment toolchain |
+| [S00-020](tasks/S00-020.md) | S00 | ci-cd | qa | review | auto-ci-cd-2a0186c54ce9 | S00-001, S00-002, S00-017, S00-018, S00-019, S00-024 | Restore access to the pinned Linux XMPP experiment toolchain |
 | [S00-021](tasks/S00-021.md) | S00 | crypto | security | done | auto-crypto-fcef9b6781bf | S00-001, S00-002 | Устранить прерывание: Проверить browser OMEMO backend |
 | [S00-022](tasks/S00-022.md) | S00 | crypto | security | blocked | auto-crypto-316a193d6c3e | S00-001, S00-002, S00-021, S00-027 | Confirm or source a verified browser/WASM-capable OMEMO2 backend for the Web client endpoint |
 | [S00-023](tasks/S00-023.md) | S00 | storage | qa | blocked | auto-storage-87486895c792 | S00-002, S00-025 | Устранить прерывание: Выбрать IndexedDB wrapper и migration policy |