feat(system):优化后端

1.新增后端测试
2.增加了后端的加密
3.增加了i18n（国际化）

tests/unit/test_utils_error.py

@@ -0,0 +1,88 @@
+"""kilostar.utils.error 类型层级与状态码测试。
+
+异常体系两条主轴：
+- ``BusinessError``：4xx；
+- ``InfraError``：5xx，下分 ``RetryableError`` / ``NonRetryableError``。
+"""
+
+import pytest
+
+from kilostar.utils import error
+
+
+def test_two_main_branches_under_kilostar_error():
+    assert issubclass(error.BusinessError, error.KiloStarError)
+    assert issubclass(error.InfraError, error.KiloStarError)
+    assert not issubclass(error.BusinessError, error.InfraError)
+    assert not issubclass(error.InfraError, error.BusinessError)
+
+
+def test_retryable_and_nonretryable_under_infra():
+    assert issubclass(error.RetryableError, error.InfraError)
+    assert issubclass(error.NonRetryableError, error.InfraError)
+    assert not issubclass(error.RetryableError, error.NonRetryableError)
+    assert not issubclass(error.NonRetryableError, error.RetryableError)
+
+
+def test_demand_error_is_business_4xx():
+    assert issubclass(error.DemandError, error.BusinessError)
+    assert error.DemandError.http_status == 400
+
+
+def test_workflow_exit_is_business_not_workflow_error():
+    """WorkflowExit 在新体系里是预期退出（4xx），与 WorkflowError(5xx) 完全分家。"""
+    assert issubclass(error.WorkflowExit, error.BusinessError)
+    assert not issubclass(error.WorkflowExit, error.WorkflowError)
+    assert error.WorkflowExit.http_status == 400
+
+
+@pytest.mark.parametrize(
+    "child,parent",
+    [
+        (error.UserNotExistError, error.UserError),
+        (error.UserPasswordError, error.UserError),
+        (error.ProviderNotExistError, error.ProviderError),
+        (error.UserError, error.BusinessError),
+        (error.ProviderError, error.BusinessError),
+        (error.ModelNotExistError, error.BusinessError),
+        (error.WorkflowError, error.InfraError),
+    ],
+)
+def test_subclass_hierarchy(child, parent):
+    assert issubclass(child, parent)
+
+
+@pytest.mark.parametrize(
+    "exc_cls,expected_status",
+    [
+        (error.UserNotExistError, 404),
+        (error.UserPasswordError, 401),
+        (error.ProviderNotExistError, 404),
+        (error.ModelNotExistError, 404),
+        (error.WorkflowExit, 400),
+        (error.RetryableError, 503),
+        (error.NonRetryableError, 500),
+        (error.WorkflowError, 500),
+    ],
+)
+def test_http_status_mapping(exc_cls, expected_status):
+    assert exc_cls.http_status == expected_status
+
+
+def test_each_error_has_code_attr():
+    """所有自定义异常都应带可读的 ``code``，用于 API 响应中 ``{"code": ...}``。"""
+    for cls in [
+        error.KiloStarError,
+        error.BusinessError,
+        error.InfraError,
+        error.UserNotExistError,
+        error.RetryableError,
+        error.WorkflowError,
+    ]:
+        assert isinstance(cls.code, str) and cls.code
+
+
+def test_errors_can_be_raised_and_caught():
+    with pytest.raises(error.UserNotExistError) as exc:
+        raise error.UserNotExistError("missing")
+    assert "missing" in str(exc.value)