fix(review): close the gate's fail-open paths an independent review found

An adversarial read of d88245c reproduced 15 problems; all fixed here, each
with a test that fails on the old code.

- verdict-gate: a greener verdict must be backed by the LAST fence being a
  `json` block of the right shape, with no BLOCKER in the JSON (any case),
  in `## Findings (BLOCKER)`, or a differing finding-id list; two verdict
  lines and more than one file argument are exit 2. ({}, null, lowercase
  "blocker", a trailing ```jsonc and a later json fence all gave exit 0.)
- engine-findings: a transcribed "narrower" key can no longer lower an
  engine tier; absolute paths under --repo-root match the scope; "12" lines
  parse; an empty scope is an error; out-of-scope engine findings are
  unverified (`engine:out-of-scope`) and forbid ALLOW.
- recurrence: the catch-all engine keys and keys normalised from unknown
  ones are never proposed; the same unfixed finding in two iterations is not
  a recurrence; proposals are validated before they are offered; \r/U+2028
  and damaged markers are refused; writes go through a symlinked CLAUDE.md.
  Prose points --repo at the session directory, not the git toplevel.
- Workflow substrate: engines are counted from what arrived, and the
  verdict's floor is recomputed from the coordinator's findings; now tested
  by running the script with stubbed Workflow globals. Two literal NUL bytes
  written as \u0000 (git saw the file as binary).
- Trimming keeps Pass 1's "Also flagged by" provenance; `## Declined to
  Judge` and remediation steps are required from review_version 1.1 only
  (N-1); the zero-diff review now carries the JSON block the gate needs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/validators/review-validator.mjs

@@ -126,7 +126,10 @@ export function validateReviewContent(text, opts = {}) {
   // append to a plan unchanged: `### Step R<n>: …` with `Source finding: <id>`.
   // Borrowed: review gaps become appended, numbered tasks with a source-ref,
   // never rewriting earlier ones (Spec Kit `templates/commands/converge.md:156-163`, MIT).
-  const blockerIds = blockerIdsFromBody(body);
+  // 1.1+ only (N-1 window): a 1.0 review never carried the section.
+  const v = typeof fm.review_version === 'string' ? fm.review_version.match(/^(\d+)\.(\d+)$/) : null;
+  const atLeast11 = v && (Number(v[1]) > 1 || (Number(v[1]) === 1 && Number(v[2]) >= 1));
+  const blockerIds = atLeast11 ? blockerIdsFromBody(body) : [];
   if (blockerIds.length > 0) {
     const steps = remediationStepSources(body);
     for (const id of blockerIds) {
@@ -142,6 +145,13 @@ export function validateReviewContent(text, opts = {}) {
     }
   }
 
+  // 1.1+: what the coordinator set aside is listed, never left out (ordre 5).
+  if (atLeast11 && !/^##\s+Declined to Judge\b/m.test(body)) {
+    const issueObj = issue('REVIEW_MISSING_SECTION', 'Required body section missing: ## Declined to Judge (review_version ≥ 1.1)');
+    if (strict) errors.push(issueObj);
+    else warnings.push(issueObj);
+  }
+
   for (const section of REVIEW_BODY_SECTIONS) {
     const re = new RegExp(`^##\\s+${section}\\b`, 'm');
     if (!re.test(body)) {