Fix language setting not being saved to database on admin settings page

- Added default_language field to general settings state in SettingsPage
- Replaced LanguageSelector component with simple select dropdown on settings page
- Fixed public settings endpoint to read general_default_language from database
- Language setting now properly saved when clicking Save Settings button
- Setting is correctly used by gallery login page and legal pages

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

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

frontend/src/components/gallery/ExpirationBanner.tsx

@@ -2,6 +2,7 @@ import React from 'react';
 import { AlertTriangle, Download } from 'lucide-react';
 import Countdown from 'react-countdown';
 import { parseISO } from 'date-fns';
+import { useTranslation } from 'react-i18next';
 
 interface ExpirationBannerProps {
   daysRemaining: number;
@@ -12,11 +13,12 @@ export const ExpirationBanner: React.FC<ExpirationBannerProps> = ({
   daysRemaining, 
   expiresAt 
 }) => {
+  const { t } = useTranslation();
   const expirationDate = parseISO(expiresAt);
   
   const countdownRenderer = ({ days, hours, minutes, completed }: any) => {
     if (completed) {
-      return <span>Gallery has expired</span>;
+      return <span>{t('gallery.expired')}</span>;
     } else {
       return (
         <span className="font-mono">
@@ -39,12 +41,12 @@ export const ExpirationBanner: React.FC<ExpirationBannerProps> = ({
           <div className="flex items-center">
             <AlertTriangle className="w-5 h-5 mr-2 animate-pulse" />
             <span className="font-medium">
-              Gallery expires in <Countdown date={expirationDate} renderer={countdownRenderer} />
+              {t('gallery.expiresIn', { count: daysRemaining })} <Countdown date={expirationDate} renderer={countdownRenderer} />
             </span>
           </div>
           <div className="flex items-center text-sm">
             <Download className="w-4 h-4 mr-1" />
-            <span>Download your photos now!</span>
+            <span>{t('gallery.downloadBefore')}</span>
           </div>
         </div>
       </div>