feat: support old title placeholder in title prompts

tests/test_ai.py

@@ -181,7 +181,40 @@ class AITests(TempDirMixin, unittest.TestCase):
             body = json.loads(calls[-1][0].data.decode("utf-8"))
             self.assertEqual("text-model", body["model"])
             self.assertEqual(0, body["temperature"])
-            self.assertNotIn("sk-text-secret", body["messages"][1]["content"])
+            self.assertEqual(1, len(body["messages"]))
+            self.assertIn("优化标题", body["messages"][0]["content"])
+            self.assertIn("旧标题：\n旧标题", body["messages"][0]["content"])
+            self.assertIn("请只返回新标题，不要解释。", body["messages"][0]["content"])
+            self.assertNotIn("sk-text-secret", body["messages"][0]["content"])
+
+        self.assert_removed(temp_dir)
+
+    def test_gen_title_renders_old_title_placeholder_without_duplicate_append(self):
+        with self.make_temp_dir() as temp_dir:
+            models_path = os.path.join(temp_dir, "ai_models.json")
+            self._write_models(models_path)
+            calls = []
+
+            def fake_urlopen(request, timeout=None):
+                calls.append(request)
+                return _Response({"choices": [{"message": {"content": "新标题"}}]})
+
+            with mock.patch("app.ai.urllib.request.urlopen", side_effect=fake_urlopen):
+                title = ai.gen_title(
+                    "请基于{旧标题}重写标题，保留 {商品id}",
+                    "原始标题A",
+                    config=self._config(),
+                    models_path=models_path,
+                )
+
+            self.assertEqual("新标题", title)
+            body = json.loads(calls[-1].data.decode("utf-8"))
+            content = body["messages"][0]["content"]
+            self.assertIn("请基于原始标题A重写标题", content)
+            self.assertEqual(1, content.count("原始标题A"))
+            self.assertNotIn("旧标题：", content)
+            self.assertIn("{商品id}", content)
+            self.assertIn("请只返回新标题，不要解释。", content)
 
         self.assert_removed(temp_dir)
 
@@ -339,6 +372,33 @@ class AITests(TempDirMixin, unittest.TestCase):
 
         self.assert_removed(temp_dir)
 
+    def test_cmhub_gen_title_renders_old_title_placeholder_once(self):
+        with self.make_temp_dir() as temp_dir:
+            cfg, key_path = self._cmhub_config(temp_dir)
+            calls = []
+
+            def fake_request(method, url, **kwargs):
+                calls.append((method, url, kwargs))
+                return _RequestsResponse({"titles": ["新标题"]})
+
+            with mock.patch.object(ai._cmhub_session(), "request", side_effect=fake_request):
+                title = ai.gen_title(
+                    "请参考 {旧标题} 输出更短标题，店铺变量 {店铺}",
+                    "原始标题B",
+                    config=cfg,
+                    cmhub_config_path=key_path,
+                )
+
+            self.assertEqual("新标题", title)
+            prompt = calls[0][2]["json"]["prompt"]
+            self.assertIn("请参考 原始标题B 输出更短标题", prompt)
+            self.assertEqual(1, prompt.count("原始标题B"))
+            self.assertNotIn("旧标题：", prompt)
+            self.assertIn("{店铺}", prompt)
+            self.assertIn("请只返回新标题，不要解释。", prompt)
+
+        self.assert_removed(temp_dir)
+
     def test_cmhub_missing_config_raises_clear_error(self):
         with self.make_temp_dir() as temp_dir:
             cfg = self._config()