fix(login): 重登成功后把 CK 检测结论写回账号

登录凭据快照盖掉了 ORM 账号，on_ck_verdict 读不到 ck_check_status，新 Cookie 被丢掉。

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/test_login_attempt_isolation.py

@@ -7,6 +7,7 @@
 停止、失败、进程重启都不可能破坏账号已有的 CK。
 """
 
+from datetime import UTC, datetime
 from types import SimpleNamespace
 
 from sqlalchemy.orm import sessionmaker
@@ -171,6 +172,37 @@ class TestLoginAttemptIsolation:
         assert account.cookie_updated_at is not None
         assert account.cookie_source == "web"
 
+    def test_relogin_success_writes_ck_verdict_on_the_account(self, monkeypatch):
+        """重登成功后的复检必须写到账号上，不能写到登录器的临时对象上。
+
+        2026-10-05 生产：登录已经成功，但 `on_ck_verdict` 收到的是
+        SimpleNamespace，读 `ck_check_status` 抛异常，新 Cookie 被丢弃，
+        页面上全部是「重新登录异常（旧 Cookie 已保留）」。
+        """
+        self.account.ck_check_status = "invalid"
+        self.session.commit()
+        monkeypatch.setattr(
+            login_service,
+            "check_douyu_cookie",
+            lambda _cookie: {
+                "valid": True,
+                "message": "ok",
+                "fish_ball": 1,
+                "nickname": "n",
+                "level": 1,
+                "checked_at": datetime.now(UTC),
+            },
+        )
+
+        self._run_batch(monkeypatch, mode="relogin")
+
+        task = self._fresh(self.task_id)
+        account = self._fresh_account()
+        assert task.attempt_status == "success"
+        assert "SimpleNamespace" not in (task.attempt_message or "")
+        assert account.cookie == "new-cookie"
+        assert account.ck_check_status == "valid"
+
     def test_stopped_batch_keeps_existing_cookie(self, monkeypatch):
         self._run_batch(monkeypatch, stop=True)