fix(verdict-gate): read --repo=<dir> and refuse unknown options

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

tests/lib/verdict-gate.test.mjs

@@ -625,3 +625,68 @@ test('[M11] a 64-hex name of a branch in a SHA-1 repository is stale with the re
     assert.ok(r.stdout.includes(name), `the reason names the id as written: ${r.stdout}`);
   } finally { fx.cleanup(); }
 });
+
+// ---- M6: --repo=<dir> is read, and an unknown option is refused ----
+
+/** An ALLOW review in a throwaway directory; `fn(path)` gets its path. */
+function withAllowReview(fn) {
+  const dir = mkdtempSync(join(tmpdir(), 'verdict-gate-m6-'));
+  try {
+    const p = join(dir, 'review.md');
+    writeFileSync(p, review({ verdict: 'ALLOW', severities: ['MINOR'] }));
+    return fn(p);
+  } finally {
+    rmSync(dir, { recursive: true, force: true });
+  }
+}
+
+function gateArgs(...argv) {
+  return spawnSync(process.execPath, [GATE, ...argv], { encoding: 'utf-8', env: childEnv() });
+}
+
+test('[M6] --repo=<dir> runs the stale check', () => {
+  const fx = gateRepo();
+  try {
+    fx.commit('fix: more work', { 'a.mjs': 'export const a = 2;\n' });
+    const p = join(fx.base, 'review.md');
+    writeFileSync(p, review({ verdict: 'ALLOW', severities: ['MINOR'], scopeShaEnd: fx.reviewed }));
+    assertStale(gateArgs('--json', p, `--repo=${fx.dir}`), /a\.mjs/);
+  } finally { fx.cleanup(); }
+});
+
+test('[M6] --repo= with no value exits 2', () => {
+  withAllowReview((p) => {
+    const r = gateArgs('--json', p, '--repo=');
+    assert.equal(r.status, 2, r.stdout + r.stderr);
+    assert.match(r.stderr, /--repo= needs a value/);
+  });
+});
+
+test('[M6] an unknown option exits 2', () => {
+  withAllowReview((p) => {
+    const r = gateArgs('--bogus', p);
+    assert.equal(r.status, 2, r.stdout + r.stderr);
+    assert.match(r.stderr, /unknown option --bogus/);
+    assert.match(r.stderr, /Usage: verdict-gate\.mjs/);
+  });
+});
+
+test('[M6] an unknown --x=value option exits 2', () => {
+  withAllowReview((p) => {
+    const r = gateArgs(p, '--x=value');
+    assert.equal(r.status, 2, r.stdout + r.stderr);
+    assert.match(r.stderr, /unknown option --x=value/);
+    assert.match(r.stderr, /Usage: verdict-gate\.mjs/);
+  });
+});
+
+test('[M6] --json is accepted while --jsonx is refused', () => {
+  withAllowReview((p) => {
+    const ok = gateArgs('--json', p);
+    assert.equal(ok.status, 0, ok.stdout + ok.stderr);
+    assert.equal(JSON.parse(ok.stdout).verdict, 'ALLOW');
+    const bad = gateArgs('--jsonx', p);
+    assert.equal(bad.status, 2, bad.stdout + bad.stderr);
+    assert.match(bad.stderr, /unknown option --jsonx/);
+  });
+});