feat(product-suite): add cmhub vision AI writing

tests/test_appconfig.py

@@ -28,6 +28,7 @@ class AppConfigTests(TempDirMixin, unittest.TestCase):
             self.assertEqual(os.path.join(temp_dir, "config", "cmhub.json"), config["cmhub_config_path"])
             self.assertEqual(240, appconfig.response_timeout(config))
             self.assertFalse(appconfig.ai_config(config)["generate_cover"])
+            self.assertEqual("vision-standard", appconfig.cmhub_config(config)["vision_alias"])
             self.assertEqual("title", appconfig.ai_generate_mode(config))
             self.assertEqual("title", appconfig.shopee_update_config(config)["update_mode"])
             self.assertNotIn("allow_cover_update", appconfig.shopee_update_config(config))
@@ -153,6 +154,34 @@ class AppConfigTests(TempDirMixin, unittest.TestCase):
 
         self.assert_removed(temp_dir)
 
+    def test_cmhub_vision_alias_defaults_for_legacy_config_and_preserves_saved_value(self):
+        with self.make_temp_dir() as temp_dir:
+            config_path = os.path.join(temp_dir, "config.json")
+            with open(config_path, "w", encoding="utf-8") as fh:
+                json.dump(
+                    {
+                        "ai": {
+                            "backend": "cmhub",
+                            "cmhub": {
+                                "base_url": "https://cmhub.example.com",
+                                "title_alias": "title-standard",
+                                "image_alias": "image-hd",
+                            },
+                        }
+                    },
+                    fh,
+                    ensure_ascii=False,
+                )
+
+            legacy = appconfig.load_config(config_path)
+            self.assertEqual("vision-standard", appconfig.cmhub_config(legacy)["vision_alias"])
+
+            legacy["ai"]["cmhub"]["vision_alias"] = "vision-custom"
+            saved = appconfig.save_config(legacy, path=config_path)
+            self.assertEqual("vision-custom", appconfig.cmhub_config(saved)["vision_alias"])
+
+        self.assert_removed(temp_dir)
+
     def test_shopee_update_legacy_parallel_config_is_migrated(self):
         with self.make_temp_dir() as temp_dir:
             config_path = os.path.join(temp_dir, "config.json")