feat: Add pytest-mock dependency for generated tests

- Add pytest-mock>=3.14.0,<4.0 to dev dependencies
- Required for mocking fixtures in LLM-generated tests
- Enables mocker fixture usage in test generation
- Supports Phase 2 & 3 test validation

Phase 2 & 3 successfully generated comprehensive test files:
- batch100/test_workflow_behavioral.py: 42KB (Phase 2)
- batch101/test_config_behavioral.py: 30KB, 63 tests (Phase 3)

Infrastructure fixes complete - ready for production use

Author: silversurfer562

pyproject.toml

@@ -182,6 +182,7 @@ dev = [
     "pytest>=7.0,<10.0",  # Updated upper bound for pytest 9.x
     "pytest-asyncio>=0.21,<2.0",  # Updated for pytest-asyncio 1.x
     "pytest-cov>=4.0,<8.0",  # Updated upper bound
+    "pytest-mock>=3.14.0,<4.0",  # Mock fixtures for testing
     "pytest-xdist>=3.5.0,<4.0",  # Parallel test execution (4-8x faster)
     "pytest-testmon>=2.1.0,<3.0",  # Run only tests affected by changes
     "pytest-picked>=0.5.0,<1.0",  # Run tests for uncommitted changes