feat: Add indicator code verification API and UI

- Add POST /api/indicator/verifyCode endpoint in Python backend.
- Update IndicatorEditor.vue with Verify Code button and error modal.
- Add i18n support for verification UI.
- Update README files.

quantdinger_vue/src/locales/lang/zh-TW.js

@@ -618,6 +618,10 @@ const locale = {
   'dashboard.indicator.editor.aiPromptRequired': '請輸入您的想法',
   'dashboard.indicator.editor.aiGenerateSuccess': '代碼生成成功',
   'dashboard.indicator.editor.aiGenerateError': '代碼生成失敗，請稍後重試',
+  'dashboard.indicator.editor.verifyCode': '代碼檢查',
+  'dashboard.indicator.editor.verifyCodeSuccess': '代碼檢查通過',
+  'dashboard.indicator.editor.verifyCodeFailed': '代碼檢查未通過',
+  'dashboard.indicator.editor.verifyCodeEmpty': '代碼不能為空',
   'dashboard.indicator.boundary.message': '提示：指標腳本只負責「計算 + 繪圖 + buy/sell 信號」；倉位、風控、加減倉、手續費/滑點屬於策略執行配置。',
   'dashboard.indicator.boundary.indicatorRule': "指標腳本請只輸出 buy/sell（並設定 df['buy']/df['sell']）。不要在腳本內撰寫倉位管理、止盈止損、加減倉。",
   'dashboard.indicator.boundary.backtestRule': '規則：同一根K線若出現主信號（buy/sell→開/平倉/反手），本K線將跳過所有加倉與減倉。',