test(question_gen): update __all__ assertion to include synthesizer exports

tests/unit/test_question_gen_api.py

@@ -35,6 +35,13 @@ class TestQuestionGenPublicAPI:
         assert hasattr(mod, "stratified_sample")
 
     def test_all_exports(self) -> None:
-        """__all__ 包含预期的公开 API。"""
+        """__all__ 包含预期的公开 API（loader + synthesizer）。"""
         mod = importlib.import_module("app.question_gen")
-        assert set(mod.__all__) == {"load_benchmark", "stratified_sample"}
+        assert set(mod.__all__) == {
+            "load_benchmark",
+            "stratified_sample",
+            "TASK_TYPE_LEVEL_MAP",
+            "AnchorContext",
+            "generate_one",
+            "sample_anchor",
+        }