fix(tests): resolve mypy divergence and test failures

- Add pydantic-ai to pre-commit mypy dependencies to fix divergence
between local mypy and CI (both now recognize Agent overloads)
- Fix JudgeHandler tests to mock get_model() which instantiates
OpenAIModel at import time (requires API key)

.pre-commit-config.yaml

@@ -15,4 +15,5 @@ repos:
           - pydantic>=2.7
           - pydantic-settings>=2.2
           - tenacity>=8.2
+          - pydantic-ai>=0.0.16
         args: [--ignore-missing-imports]

src/agent_factory/judges.py

@@ -42,7 +42,7 @@ class JudgeHandler:
             model: Optional PydanticAI model. If None, uses config default.
         """
         self.model = model or get_model()
-        self.agent = Agent(
+        self.agent = Agent(  # type: ignore[call-overload]
             model=self.model,
             result_type=JudgeAssessment,
             system_prompt=SYSTEM_PROMPT,

tests/unit/agent_factory/test_judges.py

@@ -36,7 +36,11 @@ class TestJudgeHandler:
         mock_result = MagicMock()
         mock_result.data = mock_assessment
 
-        with patch("src.agent_factory.judges.Agent") as mock_agent_class:
+        with (
+            patch("src.agent_factory.judges.get_model") as mock_get_model,
+            patch("src.agent_factory.judges.Agent") as mock_agent_class,
+        ):
+            mock_get_model.return_value = MagicMock()
             mock_agent = AsyncMock()
             mock_agent.run = AsyncMock(return_value=mock_result)
             mock_agent_class.return_value = mock_agent
@@ -86,7 +90,11 @@ class TestJudgeHandler:
         mock_result = MagicMock()
         mock_result.data = mock_assessment
 
-        with patch("src.agent_factory.judges.Agent") as mock_agent_class:
+        with (
+            patch("src.agent_factory.judges.get_model") as mock_get_model,
+            patch("src.agent_factory.judges.Agent") as mock_agent_class,
+        ):
+            mock_get_model.return_value = MagicMock()
             mock_agent = AsyncMock()
             mock_agent.run = AsyncMock(return_value=mock_result)
             mock_agent_class.return_value = mock_agent
@@ -103,7 +111,11 @@ class TestJudgeHandler:
     @pytest.mark.asyncio
     async def test_assess_handles_llm_failure(self):
         """JudgeHandler should return fallback on LLM failure."""
-        with patch("src.agent_factory.judges.Agent") as mock_agent_class:
+        with (
+            patch("src.agent_factory.judges.get_model") as mock_get_model,
+            patch("src.agent_factory.judges.Agent") as mock_agent_class,
+        ):
+            mock_get_model.return_value = MagicMock()
             mock_agent = AsyncMock()
             mock_agent.run = AsyncMock(side_effect=Exception("API Error"))
             mock_agent_class.return_value = mock_agent