phsl / new-api

Front-end enhancements around “Add custom models”:

• EditChannel.js / EditTagModal.js
  – Skip models that already exist instead of blocking the action.
  – Collect actually inserted items and display:
      • Success toast: “Added N models: model1, model2 …”
      • Info toast when no new model detected.
  – Keeps UX smooth while preserving deduplication logic.

• i18n
  – en.json: added keys
      • "已新增 {{count}} 个模型：{{list}}"
      • "未发现新增模型"
  – Fixed a broken JSON string containing smart quotes to maintain valid syntax.

Result:
Users can bulk-paste model names; duplicates are silently ignored and the UI clearly lists what was incrementally appended. All messages are fully internationalised.

Closes #1218