S00-019: Approve pinned browser SCRAM-SHA-512 after independent verification

Changes: Accept the bounded SHA-512 experiment and ADR, record independent security findings and review handoff, and retain all browser-runtime, WSS, parent-integration and production limitations.
Validation: Fresh-cache npm ci and browser build pass; 87 focused tests and 10 additional signature, verifier-flag and malformed-first checks pass. Newly installed hashed Scramp oracle verifies all three fixed exchanges. Dependency checks confirm 49 locked entries, 25 installed pins/notices and 340 unchanged Stanza files with matching artifact hashes. Canonical RFC digests and installed oracle notices agree; make check passes 72 tooling tests. Actual browser, WSS/live interoperability and release readiness remain untested.

Task: S00-019
Agent: auto-security-f465a677e48f
Role: security
Action: review
Status: done

Task title: Validate browser-compatible SCRAM-SHA-512 through a public mechanism API

state/tasks.json

@@ -1,6 +1,6 @@
 {
   "schema_version": 1,
-  "revision": 50,
+  "revision": 51,
   "tasks": {
     "S00-001": {
       "status": "done",
@@ -32,18 +32,16 @@
       "completed_at": "2026-10-14T19:06:23+00:00"
     },
     "S00-003": {
-      "status": "blocked",
-      "owner": "auto-protocol-dcdf92cd067e",
+      "status": "todo",
+      "owner": null,
       "started_at": "2026-10-14T19:35:56+00:00",
-      "reason": "Stanza 12.22.1 browser HMAC sha-512 fails RFC 4231 Test Case 1: wrong 64-byte block selection. SCRAM-SHA-512 derives that hyphenated algorithm; private algorithm mutation/vendor patches are unsupported. Parent cannot attest browser strongest-mechanism compatibility from Node-only success.",
-      "updated_at": "2026-10-14T19:38:42+00:00",
-      "blocked_by": [
-        "S00-019"
-      ],
+      "reason": null,
+      "updated_at": "2026-10-14T19:52:28+00:00",
+      "blocked_by": [],
       "resume_status": "in_progress",
       "blocker_report": "state/blockers/S00-019.md",
       "handoff": "state/handoffs/S00-003.md",
-      "previous_owner": "auto-protocol-902594b44429",
+      "previous_owner": "auto-protocol-dcdf92cd067e",
       "resumed_after_blocker": true
     },
     "S00-004": {
@@ -1249,14 +1247,17 @@
       "completed_at": "2026-10-14T19:35:55+00:00"
     },
     "S00-019": {
-      "status": "review",
+      "status": "done",
       "owner": "auto-crypto-c68801170fa4",
       "external_wait": false,
       "reason": null,
       "started_at": "2026-10-14T19:38:43+00:00",
-      "updated_at": "2026-10-14T19:48:39+00:00",
+      "updated_at": "2026-10-14T19:52:28+00:00",
       "evidence": "state/evidence/S00-019-auto-crypto-c68801170fa4.md",
-      "handoff": "state/handoffs/S00-019.md"
+      "handoff": "state/handoffs/S00-019.md",
+      "reviewer": "auto-security-f465a677e48f",
+      "review_evidence": "state/evidence/S00-019-review.md",
+      "completed_at": "2026-10-14T19:52:28+00:00"
     }
   },
   "events": [
@@ -1905,6 +1906,27 @@
       "to": "review",
       "reason": null,
       "evidence": "state/evidence/S00-019-auto-crypto-c68801170fa4.md"
+    },
+    {
+      "revision": 51,
+      "at": "2026-10-14T19:52:28+00:00",
+      "action": "auto-unblock",
+      "task": "S00-003",
+      "resolved_by": "S00-019",
+      "to": "todo",
+      "fresh_agent_required": true
+    },
+    {
+      "revision": 51,
+      "at": "2026-10-14T19:52:28+00:00",
+      "action": "approve",
+      "task": "S00-019",
+      "agent": "auto-security-f465a677e48f",
+      "role": "security",
+      "from": "review",
+      "to": "done",
+      "reason": null,
+      "evidence": "state/evidence/S00-019-review.md"
     }
   ],
   "retired_agents": [