test: make VAD integration tests work again with Transcription agent

ref: N25B-209

test/integration/agents/vad_agent/test_vad_agent.py

@@ -1,3 +1,4 @@
+import random
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
@@ -17,11 +18,16 @@ def streaming(mocker):
     return mocker.patch("control_backend.agents.vad_agent.Streaming")
 
 
+@pytest.fixture
+def transcription_agent(mocker):
+    return mocker.patch("control_backend.agents.vad_agent.TranscriptionAgent", autospec=True)
+
+
 @pytest.mark.asyncio
-async def test_normal_setup(streaming):
+async def test_normal_setup(streaming, transcription_agent):
     """
     Test that during normal setup, the VAD agent creates a Streaming behavior and creates audio
-    sockets.
+    sockets, and starts the TranscriptionAgent without loading real models.
     """
     vad_agent = VADAgent("tcp://localhost:12345", False)
     vad_agent.add_behaviour = MagicMock()
@@ -30,6 +36,8 @@ async def test_normal_setup(streaming):
 
     streaming.assert_called_once()
     vad_agent.add_behaviour.assert_called_once_with(streaming.return_value)
+    transcription_agent.assert_called_once()
+    transcription_agent.return_value.start.assert_called_once()
     assert vad_agent.audio_in_socket is not None
     assert vad_agent.audio_out_socket is not None
 
@@ -85,11 +93,12 @@ async def test_out_socket_creation_failure(zmq_context):
 
 
 @pytest.mark.asyncio
-async def test_stop(zmq_context):
+async def test_stop(zmq_context, transcription_agent):
     """
     Test that when the VAD agent is stopped, the sockets are closed correctly.
     """
     vad_agent = VADAgent("tcp://localhost:12345", False)
+    zmq_context.socket.return_value.bind_to_random_port.return_value = random.randint(1000, 10000)
 
     await vad_agent.setup()
     await vad_agent.stop()