CRITICAL FIX: prevent gallery pages redirecting to admin login

Users were being redirected from gallery pages to admin login due to
useLocalizedDate hook trying to fetch admin settings. Fixed by:

1. Added general_date_format to public settings endpoint
2. Created publicSettingsService for unauthenticated access
3. Updated useLocalizedDate to use public settings instead of admin
4. Fixed API interceptor to not redirect on public endpoint 401s
5. Added backups/ and test-archiver/ to .gitignore

This restores gallery access for all users.

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

Co-Authored-By: Claude <[email protected]>

frontend/src/hooks/useLocalizedDate.ts

@@ -2,16 +2,17 @@ import { useTranslation } from 'react-i18next';
 import { format as dateFnsFormat, formatDistanceToNow as dateFnsFormatDistanceToNow } from 'date-fns';
 import { de, enUS } from 'date-fns/locale';
 import { useQuery } from '@tanstack/react-query';
-import { settingsService } from '../services/settings.service';
+import { publicSettingsService } from '../services/publicSettings.service';
 
 export const useLocalizedDate = () => {
   const { i18n } = useTranslation();
   
-  // Fetch admin settings to get the date format
+  // Fetch public settings to get the date format
   const { data: settings } = useQuery({
-    queryKey: ['admin-settings-general'],
-    queryFn: () => settingsService.getSettingsByType('general'),
+    queryKey: ['public-settings'],
+    queryFn: () => publicSettingsService.getPublicSettings(),
     staleTime: 5 * 60 * 1000, // Cache for 5 minutes
+    retry: 1, // Only retry once to avoid blocking the UI
   });
   
   const getLocale = () => {