test(voyage): pin forward-compat for revision/source_annotations/annotation_digest/revision_reason — v4.2 Step 2

3 new test files, 24 cases (8 per validator):
- baseline (no annotation fields) still valid
- revision: 0 / revision: 5 accepted
- source_annotations list-of-dict accepted
- annotation_digest string accepted
- revision_reason accepted
- all 4 fields together accepted
- unrecognized future field tolerated (forward-compat policy)

Pin against future strict-key refactors. No production code change — pure regression pin.

plugins/voyage/tests/validators/review-validator-annotation-fields.test.mjs

@@ -0,0 +1,89 @@
+// tests/validators/review-validator-annotation-fields.test.mjs
+// Pin forward-compat for v4.2 annotation frontmatter fields on review.md.
+// Adding revision/source_annotations/annotation_digest/revision_reason must NOT
+// trigger REVIEW_UNKNOWN_FIELD or similar — validator is purely additive-tolerant
+// per source_findings precedent. No code change required; this test pins the policy.
+
+import { test } from 'node:test';
+import { strict as assert } from 'node:assert';
+import { validateReviewContent } from '../../lib/validators/review-validator.mjs';
+
+const BASE_REVIEW = `---
+type: trekreview
+review_version: "1.0"
+created: 2026-05-09
+task: "Annotated revision forward-compat"
+slug: ann-fwd-compat
+project_dir: .claude/projects/2026-05-09-ann-fwd-compat/
+brief_path: .claude/projects/2026-05-09-ann-fwd-compat/brief.md
+scope_sha_start: abc123
+scope_sha_end: def456
+reviewed_files_count: 1
+findings: []
+---
+
+# Review
+
+## Executive Summary
+
+Verdict: ALLOW.
+
+## Coverage
+
+| File | Treatment | Reason |
+|------|-----------|--------|
+| lib/foo.mjs | deep-review | risk |
+
+## Remediation Summary
+
+None.
+`;
+
+test('review-validator forward-compat — baseline (no annotation fields) still valid', () => {
+  const r = validateReviewContent(BASE_REVIEW, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+});
+
+test('review-validator forward-compat — accepts revision: 0', () => {
+  const t = BASE_REVIEW.replace('findings: []', 'findings: []\nrevision: 0');
+  const r = validateReviewContent(t, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+});
+
+test('review-validator forward-compat — accepts revision: 5', () => {
+  const t = BASE_REVIEW.replace('findings: []', 'findings: []\nrevision: 5');
+  const r = validateReviewContent(t, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+});
+
+test('review-validator forward-compat — accepts source_annotations alongside source-style findings', () => {
+  const inject = `\nrevision: 1\nsource_annotations:\n  - id: ANN-0001\n    target_artifact: review.md\n    target_anchor: executive-summary\n    intent: question\n    comment: "wording is ambiguous"\n    timestamp: "2026-05-09T10:00:00Z"`;
+  const t = BASE_REVIEW.replace('findings: []', 'findings: []' + inject);
+  const r = validateReviewContent(t, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+});
+
+test('review-validator forward-compat — accepts annotation_digest string', () => {
+  const t = BASE_REVIEW.replace('findings: []', 'findings: []\nrevision: 1\nannotation_digest: 0123456789abcdef');
+  const r = validateReviewContent(t, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+});
+
+test('review-validator forward-compat — accepts revision_reason for non-additive revision', () => {
+  const t = BASE_REVIEW.replace('findings: []', 'findings: []\nrevision: 2\nrevision_reason: "removed coverage section"');
+  const r = validateReviewContent(t, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+});
+
+test('review-validator forward-compat — all 4 annotation fields together still valid', () => {
+  const inject = `\nrevision: 3\nrevision_reason: "applied 2 annotations"\nannotation_digest: 0123456789abcdef\nsource_annotations:\n  - id: ANN-0001\n    target_artifact: review.md\n    target_anchor: coverage\n    intent: change`;
+  const t = BASE_REVIEW.replace('findings: []', 'findings: []' + inject);
+  const r = validateReviewContent(t, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+});
+
+test('review-validator forward-compat — unrecognized future field tolerated', () => {
+  const t = BASE_REVIEW.replace('findings: []', 'findings: []\nfuture_v4_3_key: "any"');
+  const r = validateReviewContent(t, { strict: true });
+  assert.equal(r.valid, true, JSON.stringify(r.errors));
+});