added sandbox and bash tool

tests/conftest.py

@@ -54,3 +54,29 @@ def sample_history():
         {"role": "assistance", "content": "Hi there!"},
         {"role": "user", "content": "What's 2+2?"},
     ]
+
+
+@pytest.fixture
+def mock_sandbox():
+    """Mock sandbox for unit tests."""
+    sandbox = MagicMock()
+    sandbox.run = AsyncMock(return_value="mock output\n")
+    return sandbox
+
+
+@pytest.fixture
+def crashed_sandbox():
+    """Mock sandbox that simulates a crash."""
+    sandbox = MagicMock()
+    sandbox.run = AsyncMock(side_effect=RuntimeError("Container crashed unexpectedly"))
+    return sandbox
+
+
+@pytest.fixture
+def mock_podman_client():
+    """Mock Podman client for unit tests."""
+    with patch("sandbox.session.podman.PodmanClient") as mock:
+        mock_container = MagicMock()
+        mock_container.exec_run.return_value = (0, b"mock output\n")
+        mock.return_value.containers.run.return_value = mock_container
+        yield mock, mock_container