fix:A_Memorix 缺失总结模型配置导致导入异常

修复默认值与迁移补写逻辑，并补充回归测试覆盖缺失与旧格式场景。

pytests/A_memorix_test/test_summary_importer_model_config.py

@@ -0,0 +1,48 @@
+import pytest
+
+from src.A_memorix.core.utils.summary_importer import SummaryImporter
+from src.config.model_configs import TaskConfig
+from src.services import llm_service as llm_api
+
+
+def _fake_available_models() -> dict[str, TaskConfig]:
+    return {
+        "replyer": TaskConfig(
+            model_list=["test-model"],
+            max_tokens=128,
+            temperature=0.7,
+            selection_strategy="priority",
+        )
+    }
+
+
+def test_resolve_summary_model_config_uses_auto_list_when_summarization_missing(monkeypatch):
+    monkeypatch.setattr(llm_api, "get_available_models", _fake_available_models)
+
+    importer = SummaryImporter(
+        vector_store=None,
+        graph_store=None,
+        metadata_store=None,
+        embedding_manager=None,
+        plugin_config={},
+    )
+
+    resolved = importer._resolve_summary_model_config()
+
+    assert resolved is not None
+    assert resolved.model_list == ["test-model"]
+
+
+def test_resolve_summary_model_config_rejects_legacy_string_selector(monkeypatch):
+    monkeypatch.setattr(llm_api, "get_available_models", _fake_available_models)
+
+    importer = SummaryImporter(
+        vector_store=None,
+        graph_store=None,
+        metadata_store=None,
+        embedding_manager=None,
+        plugin_config={"summarization": {"model_name": "auto"}},
+    )
+
+    with pytest.raises(ValueError, match="List\\[str\\]"):
+        importer._resolve_summary_model_config()