S00-021: Approve S00-021: independently verified browser OMEMO blocker

Changes:
- Wrote state/evidence/S00-021-review.md recording independent re-checks of the
  executor's remediation for S00-004's interruption ("Agent timed out before
  escalation").
- Reproduced both committed probes unchanged: smoke.mjs exit 0 (SMOKE_PASS,
  631-byte session record byte-for-byte reload) and wasm-unsupported.mjs exit 2
  (wasmFiles 0, native-only prebuilds), matching executor evidence exactly.
- Independently re-queried npm registry: @signalapp/libsignal (browser WASM) E404;
  @signalapp/libsignal-client 0.105.0 (native, AGPL-3.0) exists; confirms the
  browser/worker/WASM + OMEMO2 wire-layer blocker is genuine.
- Audited scope via git: commit 30f7f22 touches only the in-scope ADR
  docs/decisions/0003-crypto-library.md plus workflow metadata; experiments/**
  unchanged; working tree clean. No requirement bypass: S00-004 remains blocked,
  ADR 0003 records the honest blocker and forbids done on persistence+Ratchet alone.

Validation:
- make check: 72 tooling tests OK.
- Both probes reproduced, exit codes and output match evidence.
- Acceptance met: interruption repro row exists for next executor; original not
  declared done via bypass.

Task: S00-021
Reviewer agent: auto-security-5d2ae592b569
Role: security
Action: approve

Task: S00-021
Agent: auto-security-5d2ae592b569
Role: security
Action: review
Status: done

Task title: Устранить прерывание: Проверить browser OMEMO backend

planning/task_matrix.csv

@@ -2,7 +2,7 @@ id,stage,operator,reviewer,status,owner,depends_on,title
 S00-001,S00,orchestrator,security,done,auto-orchestrator-48aab142ecde,,Утвердить Web-профиль
 S00-002,S00,orchestrator,security,done,auto-orchestrator-68a05c587e33,"S00-001, S00-011, S00-012",Выбрать framework и build runtime
 S00-003,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,S00,crypto,security,blocked,auto-crypto-8bf3dcf711b9,"S00-001, S00-002, S00-021",Проверить browser OMEMO backend
+S00-004,S00,crypto,security,todo,,"S00-001, S00-002, S00-021",Проверить browser OMEMO backend
 S00-005,S00,storage,qa,todo,,S00-002,Выбрать IndexedDB wrapper и migration policy
 S00-006,S00,orchestrator,security,todo,,S00-002,Зафиксировать browser/reference matrix
 S00-007,S00,security,orchestrator,todo,,"S00-004, S00-005",Утвердить password и crypto unlock модель
@@ -18,7 +18,7 @@ S00-017,S00,protocol,security,done,auto-protocol-599343cd9e3f,"S00-001, S00-002"
 S00-018,S00,protocol,security,done,auto-protocol-89fe6563092c,"S00-001, S00-002, S00-017",Validate bounded standalone XML ingress for the XMPP candidate
 S00-019,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,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,S00,crypto,security,review,auto-crypto-fcef9b6781bf,"S00-001, S00-002",Устранить прерывание: Проверить browser OMEMO backend
+S00-021,S00,crypto,security,done,auto-crypto-fcef9b6781bf,"S00-001, S00-002",Устранить прерывание: Проверить browser OMEMO backend
 S00-010,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,S01,orchestrator,security,todo,,S00-010,Описать identity/model contracts
 S01-002,S01,orchestrator,security,todo,,"S00-010, S01-001",Описать async account context