S00-004: Record blocked task and remediation handoff

Changes: Preserve incomplete work and blocker metadata for S00-004. This checkpoint does not mark implementation accepted.
Validation: Session ended with status blocked.
Blocker: S00-004 acceptance requires establishing legacy/OMEMO2 AND worker/wasm AND persistence without a homegrown ratchet. Reproduced (this run) probes and live public-registry queries confirm only the audited session/ratchet engine + persistence are verified (@signalapp/libsignal-client@0.105.0, Node native addon, zero .wasm). The browser/worker/WASM deployment and the OMEMO/OMEMO2 wire layer are not available from any maintained package on the reachable registry (@signalapp/libsignal, @converse/omemo, @xmpp/omemo, omemo2, omemo-js, omemo-client, omemo-top, omemo-wasm all E404). ENC-009 forbids a homegrown algorithm/ratchet and ENC-011 forbids substituting media AES-GCM for the OMEMO2 wire format, so the spike cannot synthesize a browser backend inside S00-004 scope.

Task: S00-004
Agent: auto-crypto-fe1c81c17ded
Role: crypto
Action: claim
Status: blocked

Task title: Проверить browser OMEMO backend

planning/TASK_MATRIX.md

@@ -1,13 +1,13 @@
 # Матрица задач
 
-Generated; state revision **60**. Canonical status: state/tasks.json.
+Generated; state revision **62**. Canonical status: state/tasks.json.
 
 | ID | Этап | Оператор | Reviewer | Статус | Owner | Зависимости | Задача |
 | --- | --- | --- | --- | --- | --- | --- | --- |
 | [S00-001](tasks/S00-001.md) | S00 | orchestrator | security | done | auto-orchestrator-48aab142ecde |  | Утвердить Web-профиль |
 | [S00-002](tasks/S00-002.md) | S00 | orchestrator | security | done | auto-orchestrator-68a05c587e33 | S00-001, S00-011, S00-012 | Выбрать framework и build runtime |
 | [S00-003](tasks/S00-003.md) | S00 | protocol | qa | blocked | auto-protocol-59f4d359b339 | S00-001, S00-002, S00-017, S00-018, S00-019, S00-020 | Проверить XMPP WSS/auth библиотеку |
-| [S00-004](tasks/S00-004.md) | S00 | crypto | security | todo |  | S00-001, S00-002, S00-021 | Проверить browser OMEMO backend |
+| [S00-004](tasks/S00-004.md) | S00 | crypto | security | blocked | auto-crypto-fe1c81c17ded | S00-001, S00-002, S00-021, S00-022 | Проверить browser OMEMO backend |
 | [S00-005](tasks/S00-005.md) | S00 | storage | qa | todo |  | S00-002 | Выбрать IndexedDB wrapper и migration policy |
 | [S00-006](tasks/S00-006.md) | S00 | orchestrator | security | todo |  | S00-002 | Зафиксировать browser/reference matrix |
 | [S00-007](tasks/S00-007.md) | S00 | security | orchestrator | todo |  | S00-004, S00-005 | Утвердить password и crypto unlock модель |
@@ -24,6 +24,7 @@ Generated; state revision **60**. Canonical status: state/tasks.json.
 | [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 | in_progress | auto-ci-cd-5a18c8aa1b42 | S00-001, S00-002, S00-017, S00-018, S00-019 | 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 |  | S00-001, S00-002, S00-021 | Confirm or source a verified browser/WASM-capable OMEMO2 backend for the Web client endpoint |
 | [S00-010](tasks/S00-010.md) | S00 | qa | orchestrator | todo |  | S00-001, S00-002, S00-003, S00-004, S00-005, S00-006, S00-007, S00-008, S00-009 | Gate: Профиль и проверка стека |
 | [S01-001](tasks/S01-001.md) | S01 | orchestrator | security | todo |  | S00-010 | Описать identity/model contracts |
 | [S01-002](tasks/S01-002.md) | S01 | orchestrator | security | todo |  | S00-010, S01-001 | Описать async account context |