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"
@@ -175,10 +175,10 @@ export const DownloadBottomSheet = ({
                   </div>
                 </div>
               }
-              { selectedMode === DownloadSelectedMode.EMAIL && 
+              { 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>
               }
             </>