fix(settings): remove ineffective max reasoning effort level for Claude Code

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/i18n/messages/zh-TW.json

@@ -631,8 +631,7 @@
       "effortLevelDefault": "預設等級",
       "effortLevel_low": "低",
       "effortLevel_medium": "中",
-      "effortLevel_high": "高",
-      "effortLevelMax": "最高（僅 Opus 支援）"
+      "effortLevel_high": "高"
     },
     "dialogs": {
       "confirmDeleteProvider": "確認刪除 Provider {providerId}？",