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/entities/common/ui/download-bottom-sheet.tsx

@@ -57,7 +57,7 @@ export const DownloadBottomSheet = ({
       }, 10);
     }
     else{
-      snackBar('신청 방법을 선택하세요');
+      snackBar(t('common.selectRequestMethod'));
     }  
   };
   
@@ -108,7 +108,7 @@ export const DownloadBottomSheet = ({
       >
         <div className="bottomsheet-header">
           <div className="bottomsheet-title">
-            <h2>신청 방법을 선택하세요</h2>
+            <h2>{t('common.selectRequestMethod')}</h2>
             <button
               className="close-btn"
               type="button"
@@ -178,7 +178,7 @@ export const DownloadBottomSheet = ({
               { selectedMode === DownloadSelectedMode.EMAIL &&
                 (!optionsEmails || optionsEmails.length === 0) &&
                 <div className="error-message">
-                  <p>등록된 메일 정보가 없습니다.<br />이메일 인증정보를 사용자관리 메뉴에서 추가 후 신청하세요.</p>
+                  <p>{t('common.noRegisteredEmail')}<br />{t('common.addEmailAuthInfo')}</p>
                 </div>
               }
             </>

src/entities/support/ui/detail/notice-detail.tsx

@@ -30,6 +30,10 @@ export const NoticeDetail = ({
         seq: seq,
       };
       noticeDetail(detailParams).then((rs: NoticeDetailResponse) => {
+        if(!rs || Object.keys(rs).length === 0){
+          setDetailOn(false);
+          return;
+        }
         setResult(rs);
       }).catch((e: any) => {
         if(e.response?.data?.error?.message){

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"
         }