🐛 fix: add autouse fixture for API keys in unit tests

Add mock_openai_key fixture with autouse=True to automatically set
fake API keys for all unit tests, preventing OpenAI API key errors
when running tests in CI or local environments without credentials.

This fixes the CI failure where 7 tests were failing with:
"The api_key client option must be set either by passing api_key to
the client or by setting the OPENAI_API_KEY environment variable"

Author: webup

apps/sample-deep-agent/tests/conftest.py

@@ -1,10 +1,18 @@
 """Test configuration and fixtures."""
 
+import os
 from unittest.mock import Mock, patch
 
 import pytest
 
 
+@pytest.fixture(autouse=True)
+def mock_openai_key(monkeypatch):
+    """Mock OPENAI_API_KEY to prevent API key errors in unit tests."""
+    monkeypatch.setenv("OPENAI_API_KEY", "sk-test-fake-key-for-unit-tests")
+    monkeypatch.setenv("OPENROUTER_API_KEY", "sk-test-fake-key-for-unit-tests")
+
+
 @pytest.fixture
 def mock_model():
     """Mock chat model for testing."""

apps/sample-deep-agent/tests/unit/test_graph.py

@@ -1,5 +1,6 @@
 """Unit tests for sample deep agent graph components."""
 
+import pytest
 from unittest.mock import Mock, patch
 
 from sample_deep_agent.context import DeepAgentContext