Fix brand theme application and add comprehensive translations

- Fixed theme not being reflected on gallery and admin login pages
- Created GlobalThemeProvider to apply themes globally
- Updated gallery and admin login pages to use dynamic CSS variables
- Added complete translations for all admin sections in English and German:
  - Notifications management
  - Event view and creation
  - Photo upload functionality
  - Category management
  - Archive page view
  - Analytics dashboard
  - Branding and theme settings
  - System settings
  - CMS page management
  - Email configuration
- Fixed admin photo management display issues
- Fixed photo upload category assignment
- Added password reset functionality for galleries
- Improved error handling and user feedback

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

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

frontend/src/config/api.ts

@@ -5,6 +5,13 @@ import Cookies from 'js-cookie';
 export const ADMIN_TOKEN_KEY = 'admin_token';
 export const GALLERY_TOKEN_KEY = 'gallery_token';
 
+// Maintenance mode callback
+let maintenanceModeCallback: ((enabled: boolean) => void) | null = null;
+
+export const setMaintenanceModeCallback = (callback: (enabled: boolean) => void) => {
+  maintenanceModeCallback = callback;
+};
+
 // Create axios instance
 export const api = axios.create({
   baseURL: import.meta.env.VITE_API_URL || 'http://localhost:3001',
@@ -42,6 +49,19 @@ api.interceptors.request.use(
 api.interceptors.response.use(
   (response) => response,
   (error) => {
+    // Handle maintenance mode (503)
+    if (error.response?.status === 503) {
+      const isAdminRoute = error.config?.url?.includes('/admin');
+      const hasAdminAuth = error.config?.headers?.Authorization?.startsWith('Bearer ');
+      
+      // Only trigger maintenance mode for non-admin routes or unauthenticated admin routes
+      if (!isAdminRoute || !hasAdminAuth) {
+        if (maintenanceModeCallback) {
+          maintenanceModeCallback(true);
+        }
+      }
+    }
+    
     if (error.response?.status === 401) {
       // Clear tokens on unauthorized
       Cookies.remove(ADMIN_TOKEN_KEY);