fix(agent): close chat lifecycle safely

tests/test_lifecycle_shutdown.py

@@ -571,7 +571,7 @@ def test_stop_modules_continues_after_internal_owner_failures(monkeypatch):
 
 
 def test_stop_modules_drains_web_agent_tasks_before_persistence(monkeypatch):
-    """关闭时先关闭持久化准入，再收口 Web Agent 和已有写入。"""
+    """关闭时先收口 Web Agent，再关闭持久化准入和数据库任务。"""
     order = []
     monkeypatch.setattr(modules_initializer, "stop_agent", AsyncMock())
     dependencies = _patch_module_shutdown_dependencies(monkeypatch)
@@ -599,12 +599,53 @@ def test_stop_modules_drains_web_agent_tasks_before_persistence(monkeypatch):
 
     asyncio.run(modules_initializer.stop_modules())
 
-    assert order == [
-        "persistence-admission",
-        "web-agent",
-        "persistence",
-        "database",
-    ]
+    assert order == ["web-agent", "persistence-admission", "persistence", "database"]
+
+
+@pytest.mark.asyncio
+async def test_shutdown_timeout_does_not_skip_database_worker_cleanup(monkeypatch):
+    """模块关闭超时取消当前步骤后仍应继续收口数据库 worker。"""
+    started = asyncio.Event()
+
+    async def blocked_web_agent_shutdown():
+        started.set()
+        await asyncio.Event().wait()
+
+    monkeypatch.setattr(modules_initializer, "stop_agent", AsyncMock())
+    _patch_module_shutdown_dependencies(monkeypatch)
+    monkeypatch.setattr(
+        modules_initializer,
+        "shutdown_web_agent_background_tasks",
+        blocked_web_agent_shutdown,
+    )
+    monkeypatch.setattr(
+        modules_initializer,
+        "wait_web_agent_background_tasks",
+        AsyncMock(),
+    )
+    persistence = MagicMock()
+    persistence.begin_shutdown = MagicMock()
+    persistence.shutdown = AsyncMock()
+    monkeypatch.setattr(
+        modules_initializer,
+        "get_configured_agent_chat_persistence",
+        MagicMock(return_value=persistence),
+    )
+    stop_database_worker = AsyncMock()
+    monkeypatch.setattr(modules_initializer, "stop_database_worker", stop_database_worker)
+    monkeypatch.setattr(modules_initializer, "_database_worker", object())
+
+    shutdown = asyncio.create_task(
+        lifecycle.run_shutdown_step(
+            "模块服务",
+            modules_initializer.stop_modules,
+            timeout_seconds=0.01,
+        )
+    )
+    await started.wait()
+    await shutdown
+
+    stop_database_worker.assert_awaited_once_with()
 
 
 def _patch_module_shutdown_dependencies(monkeypatch) -> dict: