Fix general settings route and req.user references

- Update frontend settings service to use correct /api/admin/settings/general route
- Fix all req.user to req.admin references in adminSettings.js
- Ensures settings can be saved without authentication errors

frontend/src/hooks/useGallery.ts

@@ -2,10 +2,10 @@ import { useQuery, useMutation } from '@tanstack/react-query';
 import { galleryService } from '../services';
 import { toast } from 'react-toastify';
 
-export const useGalleryInfo = (slug: string) => {
+export const useGalleryInfo = (slug: string, token?: string) => {
   return useQuery({
-    queryKey: ['gallery-info', slug],
-    queryFn: () => galleryService.getGalleryInfo(slug),
+    queryKey: ['gallery-info', slug, token],
+    queryFn: () => galleryService.getGalleryInfo(slug, token),
     retry: 1,
     staleTime: 5 * 60 * 1000, // 5 minutes
   });