fix(voyage): inject plan_critic via Phase 9 readAndUpdate (906f155d)

plugins/voyage/tests/lib/doc-consistency.test.mjs

@@ -625,3 +625,24 @@ test('docs/annotation-quickstart.md exists with ≤7 numbered steps and example-
     `${path} must reference the canonical example fixture for hands-on verification`,
   );
 });
+
+test('commands/trekplan.md Phase 9 documents plan_critic injection via readAndUpdate (906f155d)', () => {
+  // Phase 9 (adversarial review) writes the plan-critic verdict back into
+  // plan.md frontmatter AFTER plan-review-dedup completes. The inject must
+  // happen post-Phase-8 (write) because Phase 8 precedes Phase 9 in the
+  // pipeline — the value cannot be in Phase 8's frontmatter template.
+  // Both the field name (plan_critic) and the inject mechanism
+  // (readAndUpdate from lib/util/markdown-write.mjs) must be documented
+  // so future maintainers can trace the contract.
+  const text = read('commands/trekplan.md');
+  assert.match(
+    text,
+    /plan_critic/,
+    'commands/trekplan.md must document plan_critic frontmatter field (906f155d)',
+  );
+  assert.match(
+    text,
+    /readAndUpdate/,
+    'commands/trekplan.md must reference readAndUpdate from lib/util/markdown-write.mjs (906f155d)',
+  );
+});