fix: persist visitor handover tickets anonymously

tests/unit/service/test_agent_persistence_handover.py

@@ -26,12 +26,14 @@ class FakeSession:
         self.run = run
         self.added: list[Any] = []
         self.executed: list[Any] = []
+        self._scalar_calls = 0
 
     def begin(self) -> FakeTransaction:
         return FakeTransaction()
 
-    async def scalar(self, statement: object) -> AgentRun:
-        return self.run
+    async def scalar(self, statement: object) -> object:
+        self._scalar_calls += 1
+        return self.run if self._scalar_calls == 1 else self.run.user_id
 
     def add(self, item: Any) -> None:
         self.added.append(item)
@@ -105,6 +107,33 @@ async def test_transfer_required_result_creates_pending_ticket_and_outbox_event(
     assert transfer_event.payload["ticket_no"] == tickets[0].ticket_no
 
 
+class VisitorSession(FakeSession):
+    """模拟访客运行：运行记录存在，但不存在对应的正式 sys_user。"""
+
+    def __init__(self, run: AgentRun) -> None:
+        super().__init__(run)
+
+    async def scalar(self, statement: object) -> object:
+        self._scalar_calls += 1
+        if self._scalar_calls == 1:
+            return self.run
+        return None
+
+
+@pytest.mark.asyncio
+async def test_visitor_transfer_ticket_does_not_use_anonymous_id_as_customer_fk() -> None:
+    """访客转人工写匿名工单，customer_id 必须为空而不是随机访客 ID。"""
+    session = VisitorSession(queued_run())
+
+    await AgentPersistenceService(session).complete_run(
+        "run-transfer-1", result(transfer_required=True), memory_extraction_requested=False
+    )
+
+    tickets = added_of(session.added, HandoverTicket)
+    assert len(tickets) == 1
+    assert tickets[0].customer_id is None
+
+
 @pytest.mark.asyncio
 async def test_normal_result_does_not_create_handover_ticket_or_event() -> None:
     """非转人工回答不得污染管理员待处理队列。"""