修复高风险预警邮件通知并补充测试

tests/unit/service/test_risk_scan_notification.py

@@ -38,6 +38,8 @@ class _FakeNotificationService:
     def __init__(self, *, fail: bool = False) -> None:
         self.fail = fail
         self.in_app: list[str] = []
+        self.mail_records: list[Any] = []
+        self.mail_marks: list[tuple[str, str | None]] = []
 
     def create_in_app(self, alert: Any, **kwargs: Any) -> None:
         if self.fail:
@@ -47,6 +49,22 @@ class _FakeNotificationService:
     def create_mail_record(self, alert: Any, **kwargs: Any) -> None:
         if self.fail:
             raise RuntimeError("邮件记录写库失败")
+        notification = SimpleNamespace(
+            alert=alert,
+            send_status="待发送",
+            sent_at=None,
+            fail_reason=None,
+        )
+        self.mail_records.append(notification)
+        return notification
+
+    def mark_mail_sent(self, notification: Any) -> None:
+        self.mail_marks.append(("sent", None))
+        notification.send_status = "已发送"
+
+    def mark_mail_failed(self, notification: Any, reason: str) -> None:
+        self.mail_marks.append(("failed", reason))
+        notification.send_status = "发送失败"
 
 
 def _alert(level: str, alert_no: str = "ALTEST") -> Any: