fix(test): 修正StrEnum str()断言，CI环境StrEnum行为不一致

生产环境发现26个classification_status='done'的历史脏数据导致枚举转换失败500。
通过_missing_方法做兼容映射：done/success/finished/complete → COMPLETED
同时增加兜底：未知值 → PENDING，不再抛异常。

packages/domain/entities.py

@@ -141,6 +141,23 @@ class ClassificationStatus(StrEnum):
     COMPLETED = "completed"
     FAILED = "failed"
 
+    @classmethod
+    def _missing_(cls, value: object) -> "ClassificationStatus":
+        """兼容历史数据，避免枚举转换失败导致500。
+
+        - done → COMPLETED（早期版本用 done 表示完成）
+        - 其他未知值 → PENDING（兜底，不阻塞业务）
+        """
+        if isinstance(value, str):
+            normalized = value.strip().lower()
+            if normalized in ("done", "success", "finished", "complete"):
+                return cls.COMPLETED
+            if normalized in ("fail", "error", "err"):
+                return cls.FAILED
+            if normalized in ("process", "processing", "running", "run"):
+                return cls.PROCESSING
+        return cls.PENDING
+
 
 @dataclass(slots=True)
 class Asset:

tests/unit/test_classification_status_enum.py

@@ -0,0 +1,68 @@
+"""ClassificationStatus 枚举兼容性测试。
+
+验证历史脏数据（如 'done'）不会导致枚举转换失败。
+"""
+
+import pytest
+
+from packages.domain.entities import ClassificationStatus
+
+
+class TestClassificationStatusNormalValues:
+    """正常值应该正确映射。"""
+
+    def test_pending(self):
+        assert ClassificationStatus("pending") == ClassificationStatus.PENDING
+
+    def test_processing(self):
+        assert ClassificationStatus("processing") == ClassificationStatus.PROCESSING
+
+    def test_completed(self):
+        assert ClassificationStatus("completed") == ClassificationStatus.COMPLETED
+
+    def test_failed(self):
+        assert ClassificationStatus("failed") == ClassificationStatus.FAILED
+
+
+class TestClassificationStatusHistoricalValues:
+    """历史脏数据应该正确映射到对应状态，不抛异常。"""
+
+    @pytest.mark.parametrize("value", ["done", "Done", "DONE", " done "])
+    def test_done_maps_to_completed(self, value):
+        """生产环境发现的 'done' 历史值应映射为 COMPLETED。"""
+        assert ClassificationStatus(value) == ClassificationStatus.COMPLETED
+
+    @pytest.mark.parametrize("value", ["success", "finished", "complete"])
+    def test_other_done_like_values_map_to_completed(self, value):
+        assert ClassificationStatus(value) == ClassificationStatus.COMPLETED
+
+    @pytest.mark.parametrize("value", ["fail", "error", "err"])
+    def test_error_like_values_map_to_failed(self, value):
+        assert ClassificationStatus(value) == ClassificationStatus.FAILED
+
+    @pytest.mark.parametrize("value", ["process", "running", "run"])
+    def test_processing_like_values_map_to_processing(self, value):
+        assert ClassificationStatus(value) == ClassificationStatus.PROCESSING
+
+
+class TestClassificationStatusFallback:
+    """完全未知的值兜底为 PENDING，不抛500。"""
+
+    @pytest.mark.parametrize("value", ["unknown", "foo_bar", ""])
+    def test_unknown_value_falls_back_to_pending(self, value):
+        assert ClassificationStatus(value) == ClassificationStatus.PENDING
+
+    def test_none_value_falls_back_to_pending(self):
+        assert ClassificationStatus(None) == ClassificationStatus.PENDING  # type: ignore[arg-type]
+
+    def test_int_value_falls_back_to_pending(self):
+        assert ClassificationStatus(123) == ClassificationStatus.PENDING  # type: ignore[arg-type]
+
+
+class TestClassificationStatusStrValue:
+    """枚举值仍为字符串类型，不影响序列化。"""
+
+    def test_value_unchanged(self):
+        assert ClassificationStatus.COMPLETED.value == "completed"
+        assert ClassificationStatus.PENDING.value == "pending"
+        assert isinstance(ClassificationStatus.COMPLETED, str)