Implement complete frontend with admin panel and theme system

- Add admin authentication and dashboard
- Create event management pages (list, create, edit, archive)
- Implement gallery enhancements (search, sorting, bulk download)
- Add email configuration and archive management pages
- Integrate Umami analytics with tracking throughout the app
- Add comprehensive error boundaries and loading states
- Implement accessibility features (WCAG 2.1 AA compliance)
- Create theme system with preset themes and customization
- Add branding settings and company information management
- Fix backend database initialization and health check
- Configure proper API URLs and environment variables

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

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

frontend/src/lib/utils.ts

@@ -0,0 +1,6 @@
+import { clsx, type ClassValue } from 'clsx';
+import { twMerge } from 'tailwind-merge';
+
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs));
+}