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/ko.json

@@ -631,8 +631,7 @@
       "effortLevelDefault": "기본 수준",
       "effortLevel_low": "낮음",
       "effortLevel_medium": "중간",
-      "effortLevel_high": "높음",
-      "effortLevelMax": "최고 (Opus만 지원)"
+      "effortLevel_high": "높음"
     },
     "dialogs": {
       "confirmDeleteProvider": "Provider {providerId}를 삭제하시겠습니까?",