fix: make VAD unit tests work with minimal dependencies

By mocking PyTorch and ZMQ and adding the Numpy dependency.

ref: N25B-213

test/unit/agents/test_vad_streaming.py

@@ -18,6 +18,9 @@ def audio_out_socket():
 
 @pytest.fixture
 def streaming(audio_in_socket, audio_out_socket):
+    import torch
+
+    torch.hub.load.return_value = (..., ...)  # Mock
     return Streaming(audio_in_socket, audio_out_socket)
 
 

test/unit/conftest.py

@@ -33,3 +33,13 @@ def pytest_configure(config):
     mock_config_module.settings = MagicMock()
 
     sys.modules["control_backend.core.config"] = mock_config_module
+
+    # --- Mock torch and zmq for VAD ---
+    mock_torch = MagicMock()
+    mock_zmq = MagicMock()
+    mock_zmq.asyncio = mock_zmq
+
+    # In individual tests, these can be imported and the return values changed
+    sys.modules["torch"] = mock_torch
+    sys.modules["zmq"] = mock_zmq
+    sys.modules["zmq.asyncio"] = mock_zmq.asyncio