🔠 refactor: refine group label formatting in price info

Summary:
• Updated `helpers/utils.js` to display the “group” label without a colon, ensuring consistent typography with other price elements.

Details:
1. `formatPriceInfo`
   – Changed `{t('分组')}:` to `{t('分组')}` for a cleaner look.
   – Keeps spacing intact between label and selected group name.
2. No functional impact; purely visual polish.

web/src/i18n/locales/en.json

@@ -1916,5 +1916,6 @@
   "前缀名称匹配": "Prefix name matching",
   "后缀名称匹配": "Suffix name matching",
   "包含名称匹配": "Contains name matching",
-  "展开更多": "Expand more"
+  "展开更多": "Expand more",
+  "已切换至最优倍率视图，每个模型使用其最低倍率分组": "Switched to the optimal ratio view, each model uses its lowest ratio group"
 }