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/package-lock.json

@@ -20,7 +20,8 @@
         "react-image-gallery": "^1.2.11",
         "react-intersection-observer": "^9.4.3",
         "react-router-dom": "^6.8.0",
-        "react-toastify": "^9.1.1"
+        "react-toastify": "^9.1.1",
+        "tailwind-merge": "^3.3.1"
       },
       "devDependencies": {
         "@eslint/js": "^9.29.0",
@@ -4408,6 +4409,16 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
+    "node_modules/tailwind-merge": {
+      "version": "3.3.1",
+      "resolved": "https://registry.npmjs.org/tailwind-merge/-/tailwind-merge-3.3.1.tgz",
+      "integrity": "sha512-gBXpgUm/3rp1lMZZrM/w7D8GKqshif0zAymAhbCyIt8KMe+0v9DQ7cdYLR4FHH/cKpdTXb+A/tKKU3eolfsI+g==",
+      "license": "MIT",
+      "funding": {
+        "type": "github",
+        "url": "https://github.com/sponsors/dcastil"
+      }
+    },
     "node_modules/tailwindcss": {
       "version": "3.4.17",
       "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-3.4.17.tgz",