test(#830): bound promote lost-ack residual

packages/mosaic/src/mutator-gate/mutator-gate.acceptance.spec.ts

@@ -450,6 +450,66 @@ describe('whole mutator-class lease gate', () => {
     });
   });
 
+  test('promote-lease-lost-ACK orphaned VERIFIED lease is caught by observer revoke and by monotonic TTL expiry (D2-v5 backstop)', async () => {
+    const { socket } = await startBroker();
+    const observerSessionId = await register(socket);
+    const observerPending = await beginVerification(socket, observerSessionId, 'claude');
+    await promote(socket, observerSessionId, observerPending.promotion_token!);
+
+    expect(await authorize(socket, observerSessionId, 'claude', 'Bash')).toMatchObject({
+      ok: true,
+      decision: 'allow',
+      state: 'VERIFIED',
+    });
+    const retriedPromotion = await promote(
+      socket,
+      observerSessionId,
+      observerPending.promotion_token!,
+    );
+    expect(retriedPromotion.ok).toBe(false);
+    expect(['PROMOTION_TOKEN_MISMATCH', 'INVALID_LEASE_TRANSITION']).toContain(
+      retriedPromotion.code,
+    );
+
+    const revoked = spawnSync(
+      'python3',
+      [revokerPath, '--runtime', 'claude', '--reason', 'session-start-compact'],
+      {
+        encoding: 'utf8',
+        env: {
+          ...process.env,
+          MOSAIC_LEASE_BROKER_SOCKET: socket,
+          MOSAIC_LEASE_SESSION_ID: observerSessionId,
+          MOSAIC_RUNTIME_GENERATION: '1',
+        },
+      },
+    );
+    expect(revoked.status, revoked.stderr).toBe(0);
+    expect(await authorize(socket, observerSessionId, 'claude', 'Write')).toMatchObject({
+      ok: false,
+      code: 'MUTATOR_UNVERIFIED',
+      decision: 'deny',
+    });
+
+    const { socket: expirySocket } = await startBroker();
+    const expirySessionId = await register(expirySocket);
+    expect(expirySessionId).not.toBe(observerSessionId);
+    const expiryPending = await beginVerification(expirySocket, expirySessionId, 'claude', 1, 1);
+    await promote(expirySocket, expirySessionId, expiryPending.promotion_token!);
+    expect(await authorize(expirySocket, expirySessionId, 'claude', 'Bash')).toMatchObject({
+      ok: true,
+      decision: 'allow',
+      state: 'VERIFIED',
+    });
+
+    await new Promise((resolve) => setTimeout(resolve, 1_100));
+    expect(await authorize(expirySocket, expirySessionId, 'claude', 'Bash')).toMatchObject({
+      ok: false,
+      code: 'LEASE_EXPIRED',
+      decision: 'deny',
+    });
+  });
+
   test('a fired observer fences the old lease even while broker transport is unavailable', async () => {
     const { socket } = await startBroker();
     const sessionId = await register(socket);