fix(gates): the shim reads a bare --gates and closed as on, and never swallows the next flag

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

tests/lib/autonomy-gate.test.mjs

@@ -145,3 +145,49 @@ test('CLI shim missing required args returns usage error (exit 1)', () => {
   assert.equal(parsed.ok, false);
   assert.match(parsed.error, /usage:/);
 });
+
+// ---- --gates value rule (fix round 4.5a, #1) ---------------------------------
+// The shim is tested only through its CLI; the exit code is asserted before
+// any JSON.parse, so a crash or a usage error never reads as a wrong value.
+
+function shimState(args) {
+  const r = runShim(args);
+  assert.equal(r.code, 0, `expected exit 0 for ${JSON.stringify(args)}, got ${r.code}: ${r.out}`);
+  const parsed = JSON.parse(r.out.trim());
+  assert.equal(parsed.ok, true);
+  return parsed.next_state;
+}
+
+test('[#1] bare --gates as the last argument → gates_on', () => {
+  assert.equal(shimState(['--state', 'idle', '--event', 'start', '--gates']), 'gates_on');
+});
+
+test('[#1] bare --gates before other flags swallows none of them → exit 0, gates_on', () => {
+  assert.equal(shimState(['--gates', '--state', 'idle', '--event', 'start']), 'gates_on');
+});
+
+test('[#1] --gates closed → gates_on', () => {
+  assert.equal(shimState(['--state', 'idle', '--event', 'start', '--gates', 'closed']), 'gates_on');
+});
+
+for (const bad of ['TRUE', 'yes', 'adaptive']) {
+  test(`[#1] --gates ${bad} → usage error (exit 1)`, () => {
+    const r = runShim(['--state', 'idle', '--event', 'start', '--gates', bad]);
+    assert.equal(r.code, 1, `expected exit 1 for --gates ${bad}, got ${r.code}: ${r.out}`);
+    const parsed = JSON.parse(r.out.trim());
+    assert.equal(parsed.ok, false);
+    assert.match(parsed.error, /usage/);
+  });
+}
+
+test('--gates true → gates_on', () => {
+  assert.equal(shimState(['--state', 'idle', '--event', 'start', '--gates', 'true']), 'gates_on');
+});
+
+test('--gates false → auto_running', () => {
+  assert.equal(shimState(['--state', 'idle', '--event', 'start', '--gates', 'false']), 'auto_running');
+});
+
+test('--gates open → auto_running', () => {
+  assert.equal(shimState(['--state', 'idle', '--event', 'start', '--gates', 'open']), 'auto_running');
+});