Fix login 401, admin permission, video links serialization, and admin UI styling

- Fix UserInfo boolean field naming (isAdmin → admin) for proper Jackson/MyBatis mapping
- Configure Google OAuth audience with actual client ID to fix token verification
- Parse CLOB fields and convert Oracle TIMESTAMP in restaurant video links API
- Add explicit bg-white/text-gray-900 to admin page inputs, selects, and table headers
- Add keyPrefix to RestaurantList to avoid duplicate React keys across desktop/mobile

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/app/page.tsx

@@ -392,6 +392,7 @@ export default function Home() {
       selectedId={selected?.id}
       onSelect={handleSelectRestaurant}
       loading={loading}
+      keyPrefix="d-"
     />
   );
 
@@ -415,6 +416,7 @@ export default function Home() {
       selectedId={selected?.id}
       onSelect={handleSelectRestaurant}
       loading={loading}
+      keyPrefix="m-"
     />
   );