fix: reply with standalone ping for meaningless short customer texts

tests/test_regression_pipeline.py

@@ -412,7 +412,25 @@ class RegressionPipelineTest(unittest.IsolatedAsyncioTestCase):
         self.assertTrue(resp.should_reply)
         self.assertIn("地图", resp.reply)
         self.assertIn("不做", resp.reply)
-        self.assertTrue(resp.reply.endswith(("嗯", "哦", "好的", "嗯咯", "嗯啦")))
+
+    async def test_meaningless_short_text_gets_ping_reply(self):
+        agent = CustomerServiceAgent()
+        msg = CustomerMessage(
+            msg_id="m-meaningless",
+            acc_id="test_shop",
+            msg="好的",
+            from_id=self.customer_id,
+            from_name="t",
+            cy_id=self.customer_id,
+            acc_type="AliWorkbench",
+            msg_type=0,
+            cy_name="t",
+            goods_name="专业找图",
+            goods_order="",
+        )
+        resp = await agent.process_message(msg)
+        self.assertTrue(resp.should_reply)
+        self.assertIn(resp.reply, ("嗯咯", "嗯啦", "嗯", "哦"))
 
     def tearDown(self):
         db.clear_pending_quote_state(self.customer_id)