Localize hardcoded Korean text in download-bottom-sheet and notice-detail

- Add translation keys for download bottom sheet messages
- Replace hardcoded Korean text with translation function calls
- Add error handling for empty notice detail response
- Support multi-language functionality

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/locales/en.json

@@ -50,6 +50,9 @@
         "errorOccurred": "An error occurred",
         "email": "Email",
         "kakao": "Kakao",
+        "selectRequestMethod": "Please select a request method",
+        "noRegisteredEmail": "No registered email information.",
+        "addEmailAuthInfo": "Please add email authentication information from the user management menu before applying.",
         "currency": {
             "krw": "KRW"
         }

src/locales/ko.json

@@ -50,6 +50,9 @@
         "errorOccurred": "오류가 발생했습니다",
         "email": "이메일",
         "kakao": "카카오",
+        "selectRequestMethod": "신청 방법을 선택하세요",
+        "noRegisteredEmail": "등록된 메일 정보가 없습니다.",
+        "addEmailAuthInfo": "이메일 인증정보를 사용자관리 메뉴에서 추가 후 신청하세요.",
         "currency": {
             "krw": "원"
         }