diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index a7a5b0a54..60e171b42 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -501,6 +501,14 @@ Required cases where relevant:
 
 Property-style parser tests are encouraged for high-risk parsers. They must be deterministic: pin the seed, bound the iteration count, and print replay data on failure.
 
+##### Fixture provenance (#2371)
+
+**A gate's fixtures may not be derived from the gate's own writer, grammar, or docstring examples. A negative fixture must come from a source that does not know the gate exists.**
+
+This is stricter than the adversarial-input rule above and exists because of it: `tests/fixtures/adversarial/` covers hostile input, but a fixture written by the parser's own author — even a deliberately "realistic" one — is still drawn from the author's mental model of the format. It can only ever confirm what the author already believed, never surface what they didn't anticipate. A property-test generator has the same failure mode one level up: seeding the generator from the writer/render function that produces the same format makes the document shape a constant, so the property can never explore a document the writer wouldn't produce (see the document-shaped vs. writer-seeded property tests in `tests/api-coverage.test.cjs` for a worked example — the writer-seeded one cannot fail against a decoy table; the document-shaped one can).
+
+For a gate whose fixtures come from real user reports, put them under `tests/fixtures/representative/<gate>/` with a `MANIFEST.json` labeling each fixture's source issue and expected gate verdict, and drive them through the gate's real CLI entrypoint (gate-verdict altitude), not the parser function in isolation — see `tests/fixtures/representative/README.md` and `tests/representative-corpus.test.cjs`. If the gate is not yet fixed, do not mark the assertion `{ todo: true }` and do not skip it: this repo's test-runner (`gsd-test` / `gsd-test-runner`) has no concept of node:test's `todo` option — its JSONL result parser only recognizes `kind: "pass" | "fail"`, so a thrown todo-marked test is still counted as a real failure and blocks the push gate. Instead record BOTH the correct target verdict (`expected*`) and the exact current observed verdict (`currentBuggyOutput`) in the manifest, and assert against `currentBuggyOutput` — an honest, non-vacuous characterization of today's known-broken behavior that passes today and breaks loudly the moment the real fix changes the observed output, forcing the assertion to be flipped to `expected*`.
+
 #### Filesystem writes and installers
 
 Changes to install/uninstall flows, generated artifact writers, state/config writers, worktree safety, or any code that writes under `.planning`, runtime config dirs, `.claude`, `.codex`, `hooks`, or generated files must include fault-injection coverage where the seam allows it.
diff --git a/gsd-core/bin/gsd-tools.cjs b/gsd-core/bin/gsd-tools.cjs
index f3900b475..2f31a4779 100755
--- a/gsd-core/bin/gsd-tools.cjs
+++ b/gsd-core/bin/gsd-tools.cjs
@@ -285,8 +285,6 @@ const { routeInitCommand } = require('./lib/init-command-router.cjs');
 // here, invoked from case 'init' below.
 const { warnIfStaleBake } = require('./lib/stale-bake-guard.cjs');
 const loopResolver = require('./lib/loop-resolver.cjs');
-const capabilityState = require('./lib/capability-state.cjs');
-const capabilityWriter = require('./lib/capability-writer.cjs');
 const { routePhaseCommand } = require('./lib/phase-command-router.cjs');
 const { routePhasesCommand } = require('./lib/phases-command-router.cjs');
 const { routeValidateCommand } = require('./lib/validate-command-router.cjs');
diff --git a/tests/api-coverage.test.cjs b/tests/api-coverage.test.cjs
index 9bff9ab45..68dd49868 100644
--- a/tests/api-coverage.test.cjs
+++ b/tests/api-coverage.test.cjs
@@ -20,6 +20,25 @@ const fc = require('fast-check');
 
 const MODULE_PATH = path.join(__dirname, '..', 'gsd-core', 'bin', 'lib', 'api-coverage.cjs');
 
+// Shared row-shape generators for the coverage-matrix property tests below
+// (the parse/render bijection and the #2371 document-shaped property both
+// build matrices from the same canonical row shape — a single declaration
+// here means the two properties can't silently desync).
+const capabilityGen = fc.stringMatching(/^[a-z][a-z0-9-]{0,14}$/);
+const rowGen = fc.record({
+  capability: capabilityGen,
+  decision: fc.constantFrom('INTEGRATE', 'OPT-OUT'),
+  // Reasons are short prose (e.g. "not needed yet"). The matrix is a
+  // markdown table, so cell text is format-safe: no pipes / newlines.
+  reason: fc.stringMatching(/^[a-z0-9 ,.\-!?]{0,20}$/),
+});
+// OPT-OUT rows must carry a non-empty reason for the round-trip to validate.
+const validRowGen = rowGen.map((r) =>
+  r.decision === 'OPT-OUT' && r.reason.trim() === ''
+    ? { ...r, reason: 'because' }
+    : { ...r, reason: r.reason.trim() }
+);
+
 describe('detectApiIntegration — pure detector (#1562)', () => {
   let mod;
   try {
@@ -346,20 +365,6 @@ describe('coverage matrix — parse/render bijection (fast-check)', () => {
   const { renderCoverageMatrix, validateCoverageMatrix } = mod;
 
   test('any valid row set renders and re-validates to the same counts', () => {
-    const capabilityGen = fc.stringMatching(/^[a-z][a-z0-9-]{0,14}$/);
-    const rowGen = fc.record({
-      capability: capabilityGen,
-      decision: fc.constantFrom('INTEGRATE', 'OPT-OUT'),
-      // Reasons are short prose (e.g. "not needed yet"). The matrix is a
-      // markdown table, so cell text is format-safe: no pipes / newlines.
-      reason: fc.stringMatching(/^[a-z0-9 ,.\-!?]{0,20}$/),
-    });
-    // OPT-OUT rows must carry a non-empty reason for the round-trip to validate.
-    const validRowGen = rowGen.map((r) =>
-      r.decision === 'OPT-OUT' && r.reason.trim() === ''
-        ? { ...r, reason: 'because' }
-        : { ...r, reason: r.reason.trim() }
-    );
     const matrixGen = fc.uniqueArray(validRowGen, {
       minLength: 1,
       maxLength: 8,
@@ -379,6 +384,121 @@ describe('coverage matrix — parse/render bijection (fast-check)', () => {
   });
 });
 
+// ──────────────────────────────────────────────────────────────────────────────
+// Document-shaped property (#2371): the bijection test above generates ROWS and
+// renders them through the writer, so the document shape is a constant — it
+// cannot generate a second table, a decoy table, or surrounding prose, and so
+// cannot fail against #2366's bugs. This property generates the DOCUMENT
+// space instead: a canonical matrix interleaved with content a real
+// COVERAGE.md may legitimately contain that is NOT the matrix. See
+// tests/fixtures/representative/README.md and CONTRIBUTING.md's "Fixture
+// provenance" section for the full rationale.
+// ──────────────────────────────────────────────────────────────────────────────
+
+describe('coverage matrix — document-shaped fast-check (extract-exactly-canonical, #2371)', () => {
+  let mod;
+  try {
+    mod = require(MODULE_PATH);
+  } catch (err) {
+    throw new Error(`Could not require ${MODULE_PATH}. Run "npm run build:lib" first. Underlying: ${err.message}`);
+  }
+  const { parseCoverageMatrix, renderCoverageMatrix } = mod;
+
+  // Uses the shared capabilityGen/rowGen/validRowGen declared at module scope
+  // above (same generators the bijection test uses), so the two properties
+  // exercise the same canonical-row space and can't silently desync.
+  const canonicalMatrixGen = fc.uniqueArray(validRowGen, {
+    minLength: 1,
+    maxLength: 5,
+    selector: (r) => r.capability.toLowerCase(),
+  });
+
+  // Decoy blocks: content a document may legitimately contain that is NOT the
+  // canonical matrix. Kept to three explicit, independently-readable shapes
+  // rather than a generic "random markdown" generator — a combinatorial but
+  // opaque generator is exactly the kind of cleverness that's unrunnable to
+  // debug when it fails (Kernighan's Law).
+  const proseDecoyGen = fc.constantFrom(
+    '## Notes\n\nSee the ADR for background.',
+    'This phase also touches the auth helper.',
+    '## Risks\n\n- Rollout risk is low.',
+  );
+
+  const summaryTableDecoyGen = fc
+    .record({
+      label: fc.stringMatching(/^[a-z][a-z0-9 ]{0,10}$/),
+      integrateCount: fc.nat({ max: 50 }),
+      optoutCount: fc.nat({ max: 50 }),
+    })
+    .map(
+      ({ label, integrateCount, optoutCount }) =>
+        `## Coverage summary\n\n| tier | INTEGRATE | OPT-OUT |\n|---|---|---|\n` +
+        `| ${label} | ${integrateCount} | ${optoutCount} |`
+    );
+
+  const secondSectionMatrixGen = fc
+    .uniqueArray(validRowGen, { minLength: 1, maxLength: 3, selector: (r) => r.capability.toLowerCase() })
+    .map((rows) => `## Transferred to a later phase\n\n${renderCoverageMatrix(rows)}`);
+
+  const decoyGen = fc.oneof(proseDecoyGen, summaryTableDecoyGen, secondSectionMatrixGen);
+
+  const documentGen = fc.record({
+    canonicalRows: canonicalMatrixGen,
+    decoysBefore: fc.array(decoyGen, { maxLength: 2 }),
+    decoysAfter: fc.array(decoyGen, { maxLength: 2 }),
+  });
+
+  // #2371's own test-runner (gsd-test / gsd-test-runner v1.6.2) has no concept
+  // of node:test's `todo` option: its JSONL result parser
+  // (internal/pipeline/parse.go's parseJSONL, gsd-test-runner repo) only
+  // recognizes `kind: "pass" | "fail"` and hard-errors on anything else, so a
+  // `{ todo: true }` test whose body throws is still counted as a failure in
+  // the tool's own verdict — verified directly against that source, not
+  // assumed. So this property uses fc's non-throwing `fc.check` (returns
+  // `RunDetails` instead of throwing — see fast-check's runners docs) and
+  // asserts on `.failed` directly: today the invariant genuinely does NOT
+  // hold (that is #2366), so `report.failed === true` is an honest,
+  // non-vacuous, currently-PASSING characterization of today's known-broken
+  // reality — not a fake pass. The moment #2366 makes the invariant hold for
+  // real, `report.failed` becomes `false` and THIS assertion fails loudly,
+  // forcing whoever's fix landed to notice and flip it. The fix itself stays
+  // owned by #2366.
+  test(
+    'given a document containing exactly one canonical matrix plus arbitrary other content, ' +
+      'the parser extracts exactly that matrix\'s rows and ignores everything else ' +
+      '(currently violated — #2366)',
+    () => {
+      const report = fc.check(
+        fc.property(documentGen, ({ canonicalRows, decoysBefore, decoysAfter }) => {
+          const canonicalBlock = renderCoverageMatrix(canonicalRows);
+          const doc = [...decoysBefore, canonicalBlock, ...decoysAfter].join('\n\n');
+
+          const result = parseCoverageMatrix(doc);
+
+          const expectedByCap = new Map(canonicalRows.map((r) => [r.capability.toLowerCase(), r]));
+          const actualByCap = new Map(result.rows.map((r) => [r.capability.toLowerCase(), r]));
+
+          if (actualByCap.size !== expectedByCap.size) return false;
+          for (const [cap, expected] of expectedByCap) {
+            const actual = actualByCap.get(cap);
+            if (!actual || actual.decision !== expected.decision) return false;
+          }
+          return result.errors.length === 0;
+        }),
+        { numRuns: 100 }
+      );
+      assert.strictEqual(
+        report.failed,
+        true,
+        'This property is expected to be VIOLATED today (#2366 — a decoy summary table or a ' +
+          'second canonical-schema section corrupts the result or spuriously errors). If this ' +
+          'assertion fails, the property now HOLDS — #2366 appears fixed; replace this ' +
+          'characterization with a real fc.assert of the invariant.'
+      );
+    }
+  );
+});
+
 // ──────────────────────────────────────────────────────────────────────────────
 // CLI entry point (STDIN → exit codes mirror grep, like assumption-delta)
 // ──────────────────────────────────────────────────────────────────────────────
diff --git a/tests/fixtures/golden-install-parity/antigravity.json b/tests/fixtures/golden-install-parity/antigravity.json
index c600950c3..ad0164839 100644
--- a/tests/fixtures/golden-install-parity/antigravity.json
+++ b/tests/fixtures/golden-install-parity/antigravity.json
@@ -39,7 +39,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "ea841e2865248e74",
-  "gsd-core/bin/gsd-tools.cjs": "48a2355e15c585c2",
+  "gsd-core/bin/gsd-tools.cjs": "0cfb0889b6fc5928",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/augment.json b/tests/fixtures/golden-install-parity/augment.json
index aab27bf49..b33a155e9 100644
--- a/tests/fixtures/golden-install-parity/augment.json
+++ b/tests/fixtures/golden-install-parity/augment.json
@@ -110,7 +110,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/claude-local.json b/tests/fixtures/golden-install-parity/claude-local.json
index 737959d88..2328b37e6 100644
--- a/tests/fixtures/golden-install-parity/claude-local.json
+++ b/tests/fixtures/golden-install-parity/claude-local.json
@@ -109,7 +109,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/claude.json b/tests/fixtures/golden-install-parity/claude.json
index 7017b37d9..69f8c200d 100644
--- a/tests/fixtures/golden-install-parity/claude.json
+++ b/tests/fixtures/golden-install-parity/claude.json
@@ -38,7 +38,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/cline.json b/tests/fixtures/golden-install-parity/cline.json
index 96f1f82d6..cf643a457 100644
--- a/tests/fixtures/golden-install-parity/cline.json
+++ b/tests/fixtures/golden-install-parity/cline.json
@@ -42,7 +42,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "476aa24e8c4f03cf",
-  "gsd-core/bin/gsd-tools.cjs": "bc864a9bf3a21f8b",
+  "gsd-core/bin/gsd-tools.cjs": "ecb7831b68ecb4a9",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/codebuddy.json b/tests/fixtures/golden-install-parity/codebuddy.json
index 367c000d7..35df34926 100644
--- a/tests/fixtures/golden-install-parity/codebuddy.json
+++ b/tests/fixtures/golden-install-parity/codebuddy.json
@@ -110,7 +110,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/codex.json b/tests/fixtures/golden-install-parity/codex.json
index b9219a4f3..66b1557b2 100644
--- a/tests/fixtures/golden-install-parity/codex.json
+++ b/tests/fixtures/golden-install-parity/codex.json
@@ -145,7 +145,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/copilot.json b/tests/fixtures/golden-install-parity/copilot.json
index 4ee6ae734..0fbed9dea 100644
--- a/tests/fixtures/golden-install-parity/copilot.json
+++ b/tests/fixtures/golden-install-parity/copilot.json
@@ -40,7 +40,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "ea841e2865248e74",
-  "gsd-core/bin/gsd-tools.cjs": "48a2355e15c585c2",
+  "gsd-core/bin/gsd-tools.cjs": "0cfb0889b6fc5928",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/cursor.json b/tests/fixtures/golden-install-parity/cursor.json
index 2f4d16eae..e560ebd17 100644
--- a/tests/fixtures/golden-install-parity/cursor.json
+++ b/tests/fixtures/golden-install-parity/cursor.json
@@ -110,7 +110,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "2525f1ae8b086828",
-  "gsd-core/bin/gsd-tools.cjs": "39106b83bdc47046",
+  "gsd-core/bin/gsd-tools.cjs": "6e31bf5c3515b677",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/hermes.json b/tests/fixtures/golden-install-parity/hermes.json
index 51959eb3b..876701d76 100644
--- a/tests/fixtures/golden-install-parity/hermes.json
+++ b/tests/fixtures/golden-install-parity/hermes.json
@@ -39,7 +39,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "3a3409215044af9f",
-  "gsd-core/bin/gsd-tools.cjs": "b663dd5ecf091d51",
+  "gsd-core/bin/gsd-tools.cjs": "b0385bba7000b281",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/kilo.json b/tests/fixtures/golden-install-parity/kilo.json
index fe70fd2ca..ebed16f01 100644
--- a/tests/fixtures/golden-install-parity/kilo.json
+++ b/tests/fixtures/golden-install-parity/kilo.json
@@ -110,7 +110,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/kimi.json b/tests/fixtures/golden-install-parity/kimi.json
index 77683a54c..296881790 100644
--- a/tests/fixtures/golden-install-parity/kimi.json
+++ b/tests/fixtures/golden-install-parity/kimi.json
@@ -103,7 +103,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/opencode.json b/tests/fixtures/golden-install-parity/opencode.json
index 13f95264e..38625d76a 100644
--- a/tests/fixtures/golden-install-parity/opencode.json
+++ b/tests/fixtures/golden-install-parity/opencode.json
@@ -110,7 +110,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/pi.json b/tests/fixtures/golden-install-parity/pi.json
index b48b64ac5..1c79fa95b 100644
--- a/tests/fixtures/golden-install-parity/pi.json
+++ b/tests/fixtures/golden-install-parity/pi.json
@@ -6,7 +6,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/qwen.json b/tests/fixtures/golden-install-parity/qwen.json
index 2237eb0af..4bb29b5d0 100644
--- a/tests/fixtures/golden-install-parity/qwen.json
+++ b/tests/fixtures/golden-install-parity/qwen.json
@@ -39,7 +39,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "6e98d76e955e35a2",
-  "gsd-core/bin/gsd-tools.cjs": "b0e0c49e82e33a9c",
+  "gsd-core/bin/gsd-tools.cjs": "8bdd0b02837b7a6e",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/trae.json b/tests/fixtures/golden-install-parity/trae.json
index 76c09634d..d90a49f7a 100644
--- a/tests/fixtures/golden-install-parity/trae.json
+++ b/tests/fixtures/golden-install-parity/trae.json
@@ -39,7 +39,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "de4627dff103d527",
-  "gsd-core/bin/gsd-tools.cjs": "4e19039b6a346562",
+  "gsd-core/bin/gsd-tools.cjs": "d7b5484a84a5bd15",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/windsurf.json b/tests/fixtures/golden-install-parity/windsurf.json
index 2c3e5ec65..3c5302f73 100644
--- a/tests/fixtures/golden-install-parity/windsurf.json
+++ b/tests/fixtures/golden-install-parity/windsurf.json
@@ -39,7 +39,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "5636ca0b726871b2",
-  "gsd-core/bin/gsd-tools.cjs": "196f1439ef0da939",
+  "gsd-core/bin/gsd-tools.cjs": "09a4dc673d2fd74e",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/golden-install-parity/zcode.json b/tests/fixtures/golden-install-parity/zcode.json
index 69249b4cd..111485476 100644
--- a/tests/fixtures/golden-install-parity/zcode.json
+++ b/tests/fixtures/golden-install-parity/zcode.json
@@ -110,7 +110,7 @@
   "gsd-core/VERSION": "ef0deccd81a6723c",
   "gsd-core/bin/check-latest-version.cjs": "e4a224058c8f4d74",
   "gsd-core/bin/ensure-runtime-build.cjs": "51bc64467ab30f62",
-  "gsd-core/bin/gsd-tools.cjs": "2041725176ce6b66",
+  "gsd-core/bin/gsd-tools.cjs": "48b736dd16863746",
   "gsd-core/bin/gsd_run": "62d9b647ede212e6",
   "gsd-core/bin/shared/config-defaults.manifest.json": "517e6a7c1e9f4f16",
   "gsd-core/bin/shared/config-schema.manifest.json": "0109a5a9866a24e0",
diff --git a/tests/fixtures/representative/README.md b/tests/fixtures/representative/README.md
new file mode 100644
index 000000000..2242de632
--- /dev/null
+++ b/tests/fixtures/representative/README.md
@@ -0,0 +1,82 @@
+# Representative Gate Fixtures (#2371)
+
+Every fixture in this tree is **verbatim** (or, where noted, a minimal
+faithful subset) of an artifact that a real user actually produced and
+reported against a real GSD gate. None of it was written by a gate's own
+author to exercise that gate.
+
+## Why this directory exists, and why `tests/fixtures/adversarial/` isn't enough
+
+`tests/fixtures/adversarial/` covers hostile input — unicode, CRLF, nested
+fences, heredoc breakout. Nobody attacked the gates these fixtures target.
+A developer wrote an ordinary, well-formed artifact — a plan, a coverage
+matrix, a CONTEXT.md — that a gate misjudged anyway. That input is neither
+synthetic-happy nor adversarial; it's simply *real*, and until #2371 no gate
+had coverage for it.
+
+The pattern this corpus exists to break: a gate's test fixtures were
+authored by the same person (or model) who wrote the gate, from the same
+mental model, so they can only confirm what the author already believed —
+never surface what the author didn't anticipate. See #2371 for the full
+diagnosis (four incidents across three gates in ten days, including a
+fast-check property test whose generator was seeded from the parser's own
+writer function and therefore could not fail).
+
+## Rule
+
+**A gate's fixtures may not be derived from the gate's own writer, grammar,
+or docstring examples. A negative fixture must come from a source that
+does not know the gate exists.** Recorded in `CONTRIBUTING.md` under
+"Fixture provenance."
+
+## Layout
+
+Each subdirectory is one gate:
+
+- `api-coverage-detector/` — `detectApiIntegration` (#2365)
+- `api-coverage-matrix/` — `parseCoverageMatrix` (#2366)
+- `audit-uat/` — `parseUatItems` / `parseVerificationItems` (#2286, fixed by #2317)
+- `decision-coverage-guard/` — `extractDecisions`'s could-not-parse guard (#1365 gap, #2347)
+
+Each carries its own `README.md` (what each fixture is and where it came
+from) and `MANIFEST.json` (machine-readable: file → source issue → gate →
+expected verdict). `tests/representative-corpus.test.cjs` loads every
+manifest and drives each fixture through the gate's real CLI entrypoint —
+never the parser function directly — so the assertion is at gate-verdict
+altitude (the boolean/JSON a user actually sees), not parse-tree altitude.
+
+## Why the still-broken fixtures assert `currentBuggyOutput`, not a red `todo`
+
+Three of the four gates here are still open bugs (#2365, #2366, #2347) at
+the time this corpus was added. Their `MANIFEST.json` entries carry BOTH
+the correct target verdict (`expected*` — what the eventual fix must
+produce) and the exact CURRENT observed verdict (`currentBuggyOutput` —
+what today's code actually returns). The test asserts against
+`currentBuggyOutput`: an honest, non-vacuous characterization of today's
+known-broken reality, not a fake pass.
+
+This is deliberately NOT node:test's `todo` option. `todo` looked like the
+right tool — a todo test executes and reports its failure without
+affecting Node's own process exit code
+(https://nodejs.org/api/test.html#test-options) — but this repo's actual
+test-runner (`gsd-test` / `gsd-test-runner` v1.6.2) has no concept of it:
+its JSONL result parser (`internal/pipeline/parse.go`'s `parseJSONL`, in
+the separate `gsd-test-runner` repo) only recognizes `kind: "pass" | "fail"`
+and hard-errors on anything else — verified directly against that source,
+not assumed. A `{ todo: true }` test whose body throws is still counted as
+a real failure in `gsd-test`'s own verdict, which would block the push
+gate exactly as if it weren't marked todo at all.
+
+Asserting `currentBuggyOutput` sidesteps this because the test genuinely
+passes today — no runner-level "expected failure" feature required. The
+fixes belong to #2365 / #2366 / #2347, not to this corpus. When one of
+those lands, the corresponding assertion will fail (the gate now returns
+something other than the pinned buggy value) — at that point, flip the
+test to assert `expected*` instead and delete the stale
+`currentBuggyOutput`.
+
+The `audit-uat/` corpus has no `todo`: #2286 was fixed by #2317 before this
+corpus was written, so its assertions are ordinary, currently-passing
+tests — the proof that a representative fixture, driven through the real
+gate, is not automatically doomed to fail. It demonstrates the methodology
+working, not just the gaps it finds.
diff --git a/tests/fixtures/representative/api-coverage-detector/MANIFEST.json b/tests/fixtures/representative/api-coverage-detector/MANIFEST.json
new file mode 100644
index 000000000..80dc98a30
--- /dev/null
+++ b/tests/fixtures/representative/api-coverage-detector/MANIFEST.json
@@ -0,0 +1,29 @@
+{
+  "gate": "api-coverage.verify-pre",
+  "sourceIssue": "#2365",
+  "fixtures": [
+    {
+      "file": "nextjs-route-path.txt",
+      "expectedDetected": false,
+      "currentBuggyOutput": { "detected": true, "signal": { "verb": "integration", "noun": "api" } },
+      "note": "First-party Next.js route path. The noun-boundary class [^a-zA-Z0-9] treats '/' as a word boundary, so 'api' inside the path matches as if it were prose. Highest blast radius: any Next.js project names a route file."
+    },
+    {
+      "file": "unrelated-verb-noun.txt",
+      "expectedDetected": false,
+      "currentBuggyOutput": { "detected": true, "signal": { "verb": "wiring", "noun": "endpoint" } },
+      "note": "'wiring' and 'endpoint' co-occur on one line in unrelated clauses, reverse semantic order, no integration described. The verb/noun regexes are independently exec'd over the whole line with no proximity or grammatical relation."
+    },
+    {
+      "file": "threat-model-prose.txt",
+      "expectedDetected": false,
+      "currentBuggyOutput": { "detected": true, "signal": { "verb": "(surface)", "noun": "api" } },
+      "note": "Threat-model table cell describing a LOCAL interface. SERVICE_SURFACE_API_RE matches any capitalized word before API/SDK/REST/GraphQL; the stopword denylist cannot enumerate every ordinary English word that precedes 'API' in a sentence."
+    },
+    {
+      "file": "non-integration-assertion.txt",
+      "expectedDetected": false,
+      "note": "This line explicitly ASSERTS non-integration ('no new command/dependency') and is still read as an integration signal in the real $gsd-verify-work occurrence this was drawn from — but in isolation it already returns detected:false today (the multi-signal real occurrence needed the OTHER lines' signals to trip the gate). No currentBuggyOutput: this fixture already passes for the right reason."
+    }
+  ]
+}
diff --git a/tests/fixtures/representative/api-coverage-detector/README.md b/tests/fixtures/representative/api-coverage-detector/README.md
new file mode 100644
index 000000000..8c61867f1
--- /dev/null
+++ b/tests/fixtures/representative/api-coverage-detector/README.md
@@ -0,0 +1,23 @@
+# API-coverage detector fixtures (#2365)
+
+Verbatim reproduction lines from #2365, each used as a `PLAN.md` body and
+driven through `check api-coverage.verify-pre <phaseDir>` — the real
+blocking gate, not `detectApiIntegration()` called in isolation.
+
+- `nextjs-route-path.txt` — a first-party Next.js route path read as an
+  external API signal because `/` is a word boundary.
+- `unrelated-verb-noun.txt` — a verb and a noun on the same line, unrelated
+  clauses, no compound relation.
+- `threat-model-prose.txt` — a threat-model table cell describing a LOCAL
+  interface, misread as a third-party service name.
+- `non-integration-assertion.txt` — a line that explicitly states no new
+  integration was added, misread as evidence of one.
+
+The first three currently `detected: true`; the gate expects `false` for
+all four (see `MANIFEST.json`'s `expectedDetected`/`currentBuggyOutput`
+fields). `non-integration-assertion.txt` already returns `detected: false`
+in isolation, so it's asserted directly. The other three are asserted
+against their `currentBuggyOutput` in `tests/representative-corpus.test.cjs`
+— a characterization of today's known-broken behavior, not a `todo` (see
+`tests/fixtures/representative/README.md` for why `todo` doesn't work with
+this repo's test-runner) — until #2365 lands.
diff --git a/tests/fixtures/representative/api-coverage-detector/nextjs-route-path.txt b/tests/fixtures/representative/api-coverage-detector/nextjs-route-path.txt
new file mode 100644
index 000000000..c711b9fa3
--- /dev/null
+++ b/tests/fixtures/representative/api-coverage-detector/nextjs-route-path.txt
@@ -0,0 +1 @@
+Run integration tests for src/app/api/profile/route.test.ts
\ No newline at end of file
diff --git a/tests/fixtures/representative/api-coverage-detector/non-integration-assertion.txt b/tests/fixtures/representative/api-coverage-detector/non-integration-assertion.txt
new file mode 100644
index 000000000..091523f04
--- /dev/null
+++ b/tests/fixtures/representative/api-coverage-detector/non-integration-assertion.txt
@@ -0,0 +1 @@
+Reuse existing validator APIs; no new command/dependency.
\ No newline at end of file
diff --git a/tests/fixtures/representative/api-coverage-detector/threat-model-prose.txt b/tests/fixtures/representative/api-coverage-detector/threat-model-prose.txt
new file mode 100644
index 000000000..8818574e5
--- /dev/null
+++ b/tests/fixtures/representative/api-coverage-detector/threat-model-prose.txt
@@ -0,0 +1 @@
+| Tampering | Resolver-only API rejects arbitrary caller URLs. |
\ No newline at end of file
diff --git a/tests/fixtures/representative/api-coverage-detector/unrelated-verb-noun.txt b/tests/fixtures/representative/api-coverage-detector/unrelated-verb-noun.txt
new file mode 100644
index 000000000..b95aaf924
--- /dev/null
+++ b/tests/fixtures/representative/api-coverage-detector/unrelated-verb-noun.txt
@@ -0,0 +1 @@
+Render the page and prove label endpoint, filename, and CSV/XLSX wiring.
\ No newline at end of file
diff --git a/tests/fixtures/representative/api-coverage-matrix/MANIFEST.json b/tests/fixtures/representative/api-coverage-matrix/MANIFEST.json
new file mode 100644
index 000000000..ebb110536
--- /dev/null
+++ b/tests/fixtures/representative/api-coverage-matrix/MANIFEST.json
@@ -0,0 +1,23 @@
+{
+  "gate": "api-coverage.verify-pre",
+  "sourceIssue": "#2366",
+  "fixtures": [
+    {
+      "file": "multi-table-with-summary.md",
+      "pairedPlan": "Integrate the Stripe API for payment processing.",
+      "expectedCounts": { "surface": 3, "integrate": 1, "optout": 2 },
+      "expectedErrorCount": 0,
+      "expectedBlock": false,
+      "currentBuggyOutput": {
+        "block": true,
+        "error_count": 3,
+        "errors": [
+          "row: decision \"**OPT-OUT**\" not in {INTEGRATE, OPT-OUT}",
+          "row: decision \"DECISION\" not in {INTEGRATE, OPT-OUT}",
+          "row: decision \"12\" not in {INTEGRATE, OPT-OUT}"
+        ]
+      },
+      "note": "Self-contained 15-line COVERAGE.md from #2366's own reproduction: one canonical matrix (search/skip), a second section-split canonical table (widget) for a transferred capability, and a decoy 3-column summary table whose 2nd cell reads 'INTEGRATE'. Today's parser invents a 'tier' capability from the summary table's header row (silent corruption, zero errors) and drops 'skip' (bolded decision rejected), while also spuriously erroring on the second header — the errors array above shows the rejected-DECISION-header and the rejected-bolded-OPT-OUT and rejected-numeric-'12'-cell paths, none of which mention the silently-invented 'tier' row (that corruption produces no error at all, which is the headline finding). Expected once fixed: exactly 3 rows (search, skip, widget), 0 errors — see expectedCounts/expectedErrorCount/expectedBlock."
+    }
+  ]
+}
diff --git a/tests/fixtures/representative/api-coverage-matrix/README.md b/tests/fixtures/representative/api-coverage-matrix/README.md
new file mode 100644
index 000000000..38850cd2a
--- /dev/null
+++ b/tests/fixtures/representative/api-coverage-matrix/README.md
@@ -0,0 +1,23 @@
+# API-coverage matrix fixture (#2366)
+
+`multi-table-with-summary.md` is the verbatim 15-line `repro-coverage.md`
+from #2366's own reproduction, used as a `COVERAGE.md` body and driven
+through `check api-coverage.verify-pre <phaseDir>` (paired with a PLAN.md
+that integrates an API, so a matrix is required) — the real blocking gate,
+not `parseCoverageMatrix()` called in isolation.
+
+Contains, in one file: the canonical `| capability | decision | reason |`
+matrix, a second canonical-schema table under a "Transferred to a later
+phase" heading (the section-split use case #2366 names as legitimate), and
+a decoy 3-column "Coverage summary" table whose header row happens to read
+`| tier | INTEGRATE | OPT-OUT |`.
+
+Expected once fixed: 3 rows (`search`, `skip`, `widget`), 0 errors (see
+`MANIFEST.json`'s `expectedCounts`/`expectedErrorCount`/`expectedBlock`).
+Today's parser instead invents a `tier` capability from the summary table
+(silent corruption — zero errors reported for that path) while rejecting
+the bolded `skip` decision and two other cells, producing 3 errors and
+`block: true` — pinned in `MANIFEST.json`'s `currentBuggyOutput` and
+asserted directly in `tests/representative-corpus.test.cjs` (a
+characterization of today's known-broken behavior, not a `todo` — see
+`tests/fixtures/representative/README.md` for why) until #2366 lands.
diff --git a/tests/fixtures/representative/api-coverage-matrix/multi-table-with-summary.md b/tests/fixtures/representative/api-coverage-matrix/multi-table-with-summary.md
new file mode 100644
index 000000000..200c7d92c
--- /dev/null
+++ b/tests/fixtures/representative/api-coverage-matrix/multi-table-with-summary.md
@@ -0,0 +1,18 @@
+# API Coverage — demo
+
+| capability | decision | reason |
+|---|---|---|
+| search | INTEGRATE | |
+| skip | **OPT-OUT** | not needed yet |
+
+## Transferred to a later phase
+
+| capability | decision | reason |
+|---|---|---|
+| widget | OPT-OUT | deferred to 9 |
+
+## Coverage summary
+
+| tier | INTEGRATE | OPT-OUT |
+|---|---|---|
+| phase 8 | 12 | 6 |
diff --git a/tests/fixtures/representative/audit-uat/MANIFEST.json b/tests/fixtures/representative/audit-uat/MANIFEST.json
new file mode 100644
index 000000000..3f0b7c6b4
--- /dev/null
+++ b/tests/fixtures/representative/audit-uat/MANIFEST.json
@@ -0,0 +1,20 @@
+{
+  "gate": "audit-uat",
+  "sourceIssue": "#2286",
+  "fixedBy": "#2317",
+  "fixtures": [
+    {
+      "file": "gaps-section-uat.md",
+      "filenameSuffix": "-UAT.md",
+      "expectedMinItems": 1,
+      "note": "A '## Gaps' bullet entry with status: open. Before #2317, parseUatItems never scanned this section at all, so this file's real outstanding item was silently invisible."
+    },
+    {
+      "file": "human-verification-frontmatter.md",
+      "filenameSuffix": "-VERIFICATION.md",
+      "expectedMinItems": 1,
+      "note": "Frontmatter declares status: human_needed with a populated human_verification: array. Before #2317, parseVerificationItems never read the frontmatter's structured array and only recognized specific body shapes, so this file read as zero items."
+    }
+  ],
+  "expectedTotalItems": 2
+}
diff --git a/tests/fixtures/representative/audit-uat/README.md b/tests/fixtures/representative/audit-uat/README.md
new file mode 100644
index 000000000..1f1dd8fe9
--- /dev/null
+++ b/tests/fixtures/representative/audit-uat/README.md
@@ -0,0 +1,17 @@
+# Audit-UAT fixtures (#2286, fixed by #2317)
+
+Verbatim reproduction files from #2286, driven through `gsd-tools
+audit-uat --raw` (the real CLI gate) rather than `parseUatItems` /
+`parseVerificationItems` called in isolation.
+
+- `gaps-section-uat.md` — a UAT file whose only outstanding finding lives
+  in a `## Gaps` bullet entry.
+- `human-verification-frontmatter.md` — a VERIFICATION file whose
+  frontmatter declares a structured `human_verification:` array.
+
+This is the one corpus in `tests/fixtures/representative/` with **no**
+`todo` marker. #2286 was fixed by #2317 (merged) before this corpus was
+written, so `total_items >= 2` is a normal, currently-passing assertion —
+proof that a representative fixture, driven through the real gate, is not
+automatically doomed to fail. It demonstrates the methodology working end
+to end, not just the gaps it finds in the other three gates.
diff --git a/tests/fixtures/representative/audit-uat/gaps-section-uat.md b/tests/fixtures/representative/audit-uat/gaps-section-uat.md
new file mode 100644
index 000000000..39d0fee5f
--- /dev/null
+++ b/tests/fixtures/representative/audit-uat/gaps-section-uat.md
@@ -0,0 +1,4 @@
+## Gaps
+
+- truth: "SC1: some success criterion"
+  status: open
diff --git a/tests/fixtures/representative/audit-uat/human-verification-frontmatter.md b/tests/fixtures/representative/audit-uat/human-verification-frontmatter.md
new file mode 100644
index 000000000..2f6b1bea7
--- /dev/null
+++ b/tests/fixtures/representative/audit-uat/human-verification-frontmatter.md
@@ -0,0 +1,11 @@
+---
+status: human_needed
+human_verification:
+  - test: "Confirm the widget renders correctly"
+---
+
+## Human Verification Required
+
+### 1. Widget render check
+
+**Confirm the widget appears as expected on the dashboard.**
diff --git a/tests/fixtures/representative/decision-coverage-guard/MANIFEST.json b/tests/fixtures/representative/decision-coverage-guard/MANIFEST.json
new file mode 100644
index 000000000..f51db1228
--- /dev/null
+++ b/tests/fixtures/representative/decision-coverage-guard/MANIFEST.json
@@ -0,0 +1,18 @@
+{
+  "gate": "check.decision-coverage-plan",
+  "sourceIssue": "#2347",
+  "fixtures": [
+    {
+      "file": "d5-prefix-context.md",
+      "expectedReason": "could-not-parse",
+      "expectedPassed": false,
+      "currentBuggyOutput": {
+        "passed": true,
+        "skipped": true,
+        "reason": "no trackable decisions",
+        "total": 0
+      },
+      "note": "A <decisions> block using the D5-01 ID-prefix shape from #2347's own reproduction ('- **D5-01:** some decision'), repeated twice so 'populated but 0 extracted' is unambiguous. The original report used 23 real decisions under a project-specific D5- prefix convention; this fixture preserves the exact grammar mismatch, not the count. The #1365 guard's evidence test (/\\bD-[A-Za-z0-9]/) shares the parser's own D- grammar, so it is blind to exactly the input class it exists to catch: both see nothing, and the gate reports passed:true, skipped:true, reason:'no trackable decisions' instead of failing loud."
+    }
+  ]
+}
diff --git a/tests/fixtures/representative/decision-coverage-guard/README.md b/tests/fixtures/representative/decision-coverage-guard/README.md
new file mode 100644
index 000000000..bdba0a51d
--- /dev/null
+++ b/tests/fixtures/representative/decision-coverage-guard/README.md
@@ -0,0 +1,24 @@
+# Decision-coverage guard fixture (#2347)
+
+`d5-prefix-context.md` is the verbatim reproduction shape from #2347 — the
+`- **D5-01:** some decision` bullet given in the issue's own "Steps to
+reproduce" — used as a CONTEXT.md `<decisions>` block and driven through
+`query check.decision-coverage-plan <phaseDir> <contextPath>` (the real
+CLI gate; see `tests/decisions.test.cjs` for the established pattern this
+follows), not `extractDecisions()` called in isolation.
+
+The #1365 fail-loud guard's "is this decision-shaped?" evidence test
+(`/\bD-[A-Za-z0-9]/`) reuses the same `D-` grammar as the parser it guards.
+For any ID prefix the parser cannot read — `D5-01` here — the guard sees
+no evidence either, so the two failure modes the guard exists to
+distinguish (`none-present` vs `could-not-parse`) collapse into
+`none-present`, and a populated, genuinely decision-shaped CONTEXT.md
+passes silently.
+
+Expected once fixed: `reason: 'could-not-parse'`, `passed: false` (see
+`MANIFEST.json`'s `expectedReason`/`expectedPassed`). Today's gate instead
+reports `passed: true, skipped: true, reason: 'no trackable decisions'` —
+pinned in `MANIFEST.json`'s `currentBuggyOutput` and asserted directly in
+`tests/representative-corpus.test.cjs` (a characterization of today's
+known-broken behavior, not a `todo` — see
+`tests/fixtures/representative/README.md` for why) until #2347 lands.
diff --git a/tests/fixtures/representative/decision-coverage-guard/d5-prefix-context.md b/tests/fixtures/representative/decision-coverage-guard/d5-prefix-context.md
new file mode 100644
index 000000000..0d9215ae6
--- /dev/null
+++ b/tests/fixtures/representative/decision-coverage-guard/d5-prefix-context.md
@@ -0,0 +1,4 @@
+<decisions>
+- **D5-01:** some decision
+- **D5-02:** some other decision
+</decisions>
diff --git a/tests/representative-corpus.test.cjs b/tests/representative-corpus.test.cjs
new file mode 100644
index 000000000..cc86c1073
--- /dev/null
+++ b/tests/representative-corpus.test.cjs
@@ -0,0 +1,261 @@
+'use strict';
+
+/**
+ * Representative-corpus gate tests (#2371).
+ *
+ * Every fixture under tests/fixtures/representative/ is verbatim (or a
+ * minimal faithful subset) of a real reported artifact — never invented to
+ * match a gate's own grammar. See tests/fixtures/representative/README.md
+ * for the full rationale and CONTRIBUTING.md's "Fixture provenance" rule.
+ *
+ * Each gate is driven through its real CLI entrypoint (gate-verdict
+ * altitude), matching the established pattern in
+ * tests/api-coverage-gate-e2e.test.cjs and tests/decisions.test.cjs — never
+ * the parser function called in isolation.
+ *
+ * Three fixtures (across api-coverage-detector, api-coverage-matrix,
+ * decision-coverage-guard) encode gates that are still open bugs (#2365,
+ * #2366, #2347). For those, MANIFEST.json carries BOTH the correct target
+ * verdict (`expected*` — what the fix must produce) and the exact CURRENT
+ * observed verdict (`currentBuggyOutput` — what today's code actually
+ * returns). The test asserts against `currentBuggyOutput`: an honest,
+ * non-vacuous characterization of today's known-broken reality, not a fake
+ * pass. This assertion WILL fail, loudly, the moment the underlying bug is
+ * fixed and the gate starts returning something other than the pinned
+ * buggy value — at which point whoever's fix landed must update the
+ * assertion to check `expected*` instead (and can delete `currentBuggyOutput`).
+ *
+ * Why not node:test's `todo` option: this repo's own test-runner
+ * (gsd-test / gsd-test-runner v1.6.2) has no concept of it. Its JSONL
+ * result parser (internal/pipeline/parse.go's parseJSONL, gsd-test-runner
+ * repo) only recognizes `kind: "pass" | "fail"` — verified directly against
+ * that source — so a `{ todo: true }` test whose body throws is still
+ * counted as a real failure in the tool's own verdict. Characterization
+ * (assert the known-current value) sidesteps this because the test
+ * genuinely passes today; it needs no runner-level "expected failure"
+ * feature at all.
+ *
+ * The audit-uat corpus (#2286, fixed by #2317) has no currentBuggyOutput:
+ * it already asserts the correct behavior directly, because the bug is
+ * already fixed — proof the methodology works end to end, not just a
+ * record of gaps.
+ */
+
+const { describe, test, afterEach } = require('node:test');
+const assert = require('node:assert/strict');
+const fs = require('node:fs');
+const os = require('node:os');
+const path = require('node:path');
+const { execFileSync } = require('node:child_process');
+
+const { cleanup } = require('./helpers.cjs');
+
+const TOOLS_PATH = path.join(__dirname, '..', 'gsd-core', 'bin', 'gsd-tools.cjs');
+const FIXTURES_ROOT = path.join(__dirname, 'fixtures', 'representative');
+
+const TEST_ENV_BASE = {
+  GSD_SESSION_KEY: '',
+  CODEX_THREAD_ID: '',
+  CLAUDE_SESSION_ID: '',
+  CLAUDE_CODE_SSE_PORT: '',
+  OPENCODE_SESSION_ID: '',
+  GEMINI_SESSION_ID: '',
+  CURSOR_SESSION_ID: '',
+  WINDSURF_SESSION_ID: '',
+  TERM_SESSION: '',
+  WT_SESSION: '',
+  TMUX_PANE: '',
+  ZELLIJ_SESSION_NAME: '',
+  TTY: '',
+  SSH_TTY: '',
+};
+
+function runTools(args, cwd) {
+  try {
+    const stdout = execFileSync(process.execPath, [TOOLS_PATH, ...args], {
+      cwd,
+      encoding: 'utf-8',
+      env: { ...process.env, ...TEST_ENV_BASE },
+      timeout: 60000,
+    });
+    return { success: true, output: stdout.trim(), error: '' };
+  } catch (err) {
+    return {
+      success: false,
+      output: err.stdout?.toString().trim() || '',
+      error: err.stderr?.toString().trim() || err.message,
+    };
+  }
+}
+
+function readManifest(gateDir) {
+  const raw = fs.readFileSync(path.join(FIXTURES_ROOT, gateDir, 'MANIFEST.json'), 'utf8');
+  return JSON.parse(raw);
+}
+
+function readFixture(gateDir, file) {
+  return fs.readFileSync(path.join(FIXTURES_ROOT, gateDir, file), 'utf8');
+}
+
+function makeProject() {
+  const tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), 'gsd-repcorpus-'));
+  fs.mkdirSync(path.join(tmpDir, '.planning', 'phases'), { recursive: true });
+  fs.writeFileSync(path.join(tmpDir, '.planning', 'config.json'), '{}', 'utf8');
+  return tmpDir;
+}
+
+function makePhaseDir(projectDir, slug) {
+  const dir = path.join(projectDir, '.planning', 'phases', slug);
+  fs.mkdirSync(dir, { recursive: true });
+  return dir;
+}
+
+// ─── api-coverage-detector (#2365) ────────────────────────────────────────────
+
+describe('representative corpus — api-coverage detector (#2365)', () => {
+  let tmpDir;
+  afterEach(() => { if (tmpDir) { cleanup(tmpDir); tmpDir = null; } });
+
+  const manifest = readManifest('api-coverage-detector');
+
+  for (const fx of manifest.fixtures) {
+    const label = fx.currentBuggyOutput ? `${fx.file} → currently detected:true (#2365)` : `${fx.file} → detected:false`;
+    test(label, () => {
+      tmpDir = makeProject();
+      const phaseDir = makePhaseDir(tmpDir, '01-repcorpus');
+      const body = readFixture('api-coverage-detector', fx.file);
+      fs.writeFileSync(path.join(phaseDir, '01-PLAN.md'), `# Plan\n${body}\n`, 'utf8');
+
+      const r = runTools(['check', 'api-coverage.verify-pre', phaseDir, '--raw'], tmpDir);
+      assert.ok(r.success, `gate should succeed (JSON). stderr: ${r.error}`);
+      const j = JSON.parse(r.output);
+
+      if (fx.currentBuggyOutput) {
+        assert.strictEqual(j.detected, fx.currentBuggyOutput.detected,
+          `${fx.file}: expected today's known-buggy detected:${fx.currentBuggyOutput.detected}, got ${JSON.stringify(j)}. ` +
+          `If this now differs, #2365 may be fixed — check against expectedDetected:${fx.expectedDetected} instead.`);
+        assert.strictEqual(j.signals?.[0]?.verb, fx.currentBuggyOutput.signal.verb, `${fx.file}: signal.verb`);
+        assert.strictEqual(j.signals?.[0]?.noun, fx.currentBuggyOutput.signal.noun, `${fx.file}: signal.noun`);
+      } else {
+        assert.strictEqual(j.detected, fx.expectedDetected,
+          `${fx.file}: expected detected:${fx.expectedDetected}, got ${JSON.stringify(j)}`);
+      }
+    });
+  }
+});
+
+// ─── api-coverage-matrix (#2366) ──────────────────────────────────────────────
+
+describe('representative corpus — api-coverage matrix (#2366)', () => {
+  let tmpDir;
+  afterEach(() => { if (tmpDir) { cleanup(tmpDir); tmpDir = null; } });
+
+  const manifest = readManifest('api-coverage-matrix');
+
+  for (const fx of manifest.fixtures) {
+    const label = fx.currentBuggyOutput
+      ? `${fx.file} → currently silently-corrupted + spurious errors (#2366)`
+      : `${fx.file} → exactly the canonical rows, 0 errors`;
+    test(label, () => {
+      tmpDir = makeProject();
+      const phaseDir = makePhaseDir(tmpDir, '01-repcorpus');
+      fs.writeFileSync(path.join(phaseDir, '01-PLAN.md'), `# Plan\n${fx.pairedPlan}\n`, 'utf8');
+      fs.writeFileSync(path.join(phaseDir, 'COVERAGE.md'), readFixture('api-coverage-matrix', fx.file), 'utf8');
+
+      const r = runTools(['check', 'api-coverage.verify-pre', phaseDir, '--raw'], tmpDir);
+      assert.ok(r.success, `gate should succeed (JSON). stderr: ${r.error}`);
+      const j = JSON.parse(r.output);
+
+      if (fx.currentBuggyOutput) {
+        assert.strictEqual(j.block, fx.currentBuggyOutput.block,
+          `${fx.file}: expected today's known-buggy block:${fx.currentBuggyOutput.block}, got ${JSON.stringify(j)}. ` +
+          `If this now differs, #2366 may be fixed — check against expectedBlock:${fx.expectedBlock} instead.`);
+        assert.strictEqual(j.error_count, fx.currentBuggyOutput.error_count, `${fx.file}: error_count`);
+        assert.deepStrictEqual(j.errors, fx.currentBuggyOutput.errors, `${fx.file}: errors`);
+      } else {
+        assert.strictEqual(j.block, fx.expectedBlock, `${fx.file}: block. Got ${JSON.stringify(j)}`);
+        assert.deepStrictEqual(j.counts, fx.expectedCounts, `${fx.file}: counts. Got ${JSON.stringify(j)}`);
+        assert.strictEqual((j.errors || []).length, fx.expectedErrorCount,
+          `${fx.file}: errors. Got ${JSON.stringify(j.errors)}`);
+      }
+    });
+  }
+});
+
+// ─── audit-uat (#2286, fixed by #2317 — asserts correct behavior directly) ────
+
+describe('representative corpus — audit-uat (#2286, fixed by #2317)', () => {
+  let tmpDir;
+  afterEach(() => { if (tmpDir) { cleanup(tmpDir); tmpDir = null; } });
+
+  const manifest = readManifest('audit-uat');
+
+  test('Gaps-section + human-verification-frontmatter fixtures both surface as real items', () => {
+    tmpDir = makeProject();
+    const phaseDir = makePhaseDir(tmpDir, '01-repcorpus');
+    for (const fx of manifest.fixtures) {
+      fs.writeFileSync(
+        path.join(phaseDir, `01${fx.filenameSuffix}`),
+        readFixture('audit-uat', fx.file),
+        'utf8',
+      );
+    }
+
+    const r = runTools(['audit-uat', '--raw'], tmpDir);
+    assert.ok(r.success, `audit-uat should succeed. stderr: ${r.error}`);
+    const j = JSON.parse(r.output);
+    assert.ok(
+      j.summary.total_items >= manifest.expectedTotalItems,
+      `expected total_items >= ${manifest.expectedTotalItems}, got ${JSON.stringify(j.summary)}`,
+    );
+    // Per-fixture check (not just the aggregate): a regression that moves
+    // items between files while preserving the total would slip past the
+    // total_items check above but not this one.
+    for (const fx of manifest.fixtures) {
+      const fileName = `01${fx.filenameSuffix}`;
+      const fileResult = j.results.find((r2) => r2.file === fileName);
+      assert.ok(fileResult, `expected a result entry for ${fileName}, got ${JSON.stringify(j.results)}`);
+      assert.ok(
+        fileResult.items.length >= fx.expectedMinItems,
+        `${fileName}: expected items.length >= ${fx.expectedMinItems}, got ${fileResult.items.length}`,
+      );
+    }
+  });
+});
+
+// ─── decision-coverage-guard (#2347) ──────────────────────────────────────────
+
+describe('representative corpus — decision-coverage guard (#2347)', () => {
+  let tmpDir;
+  afterEach(() => { if (tmpDir) { cleanup(tmpDir); tmpDir = null; } });
+
+  const manifest = readManifest('decision-coverage-guard');
+
+  for (const fx of manifest.fixtures) {
+    const label = fx.currentBuggyOutput
+      ? `${fx.file} → currently passed:true, skipped:true (#2347)`
+      : `${fx.file} → outcome could-not-parse, passed:false`;
+    test(label, () => {
+      tmpDir = makeProject();
+      const phaseDir = makePhaseDir(tmpDir, '01-repcorpus');
+      const contextPath = path.join(phaseDir, 'CONTEXT.md');
+      fs.writeFileSync(contextPath, readFixture('decision-coverage-guard', fx.file), 'utf8');
+
+      const r = runTools(['query', 'check.decision-coverage-plan', phaseDir, contextPath], tmpDir);
+      assert.ok(r.success, `gate should succeed (JSON). stderr: ${r.error}`);
+      const j = JSON.parse(r.output);
+
+      if (fx.currentBuggyOutput) {
+        assert.strictEqual(j.passed, fx.currentBuggyOutput.passed,
+          `${fx.file}: expected today's known-buggy passed:${fx.currentBuggyOutput.passed}, got ${JSON.stringify(j)}. ` +
+          `If this now differs, #2347 may be fixed — check against expectedPassed:${fx.expectedPassed} instead.`);
+        assert.strictEqual(j.skipped, fx.currentBuggyOutput.skipped, `${fx.file}: skipped`);
+        assert.strictEqual(j.reason, fx.currentBuggyOutput.reason, `${fx.file}: reason`);
+        assert.strictEqual(j.total, fx.currentBuggyOutput.total, `${fx.file}: total`);
+      } else {
+        assert.strictEqual(j.passed, fx.expectedPassed, `${fx.file}: passed. Got ${JSON.stringify(j)}`);
+        assert.strictEqual(j.reason, fx.expectedReason, `${fx.file}: reason. Got ${JSON.stringify(j)}`);
+      }
+    });
+  }
+});