refactor: Phase 1 code consolidation and service layer setup

Phase 1.1: Shared parsers utility
- Create backend/src/utils/parsers.js with parseBooleanInput, parseStringInput, etc.
- Create frontend/src/utils/parsers.ts with TypeScript equivalents
- Update routes to import from shared parsers

Phase 1.2: Auth routes consolidation
- Merge auth.js, auth-enhanced.js, auth-enhanced-v2.js into single auth.js
- Add password change and password strength endpoints
- Consolidate middleware (auth.js with token revocation support)
- Update all imports across 14+ route files

Phase 1.3: CreateEvent page consolidation
- Remove duplicate CreateEventPage.tsx (basic version)
- Rename CreateEventPageEnhanced.tsx to CreateEventPage.tsx
- Update exports and imports

Phase 1.4: CMS page consolidation
- Remove duplicate CMSPage.tsx (basic version)
- Rename CMSPageEnhanced.tsx to CMSPage.tsx
- Update exports and imports

Phase 1.5: Multer config factory
- Create backend/src/config/multerConfig.js
- Centralized upload configuration with presets for photos, logos, favicons
- Reusable helpers: createDiskStorage, createFileFilter, uploadTimeoutMiddleware

Phase 2.1: Event service layer
- Create backend/src/services/eventService.js
- Move event business logic out of routes
- Functions: createEvent, getAllEvents, updateEvent, deleteEvent, extendExpiration

frontend/src/App.tsx

@@ -14,7 +14,7 @@ import {
   AdminLoginPage, 
   AdminDashboard, 
   EventsListPage,
-  CreateEventPageEnhanced as CreateEventPage,
+  CreateEventPage,
   EventDetailsPage,
   EventFeedbackPage,
   EmailConfigPage,
@@ -22,9 +22,9 @@ import {
   AnalyticsPage,
   BrandingPage,
   SettingsPage,
-  BackupManagement
+  BackupManagement,
+  CMSPage
 } from './pages/admin';
-import { CMSPageEnhanced } from './pages/admin/CMSPageEnhanced';
 import { AdminLayout, AdminAuthWrapper } from './components/admin';
 import { PageErrorBoundary, OfflineIndicator, SkipLink, DynamicFavicon } from './components/common';
 import { MaintenanceWrapper } from './components/MaintenanceWrapper';
@@ -127,7 +127,7 @@ function App() {
                       <Route path="branding" element={<BrandingPage />} />
                       <Route path="settings" element={<SettingsPage />} />
                       <Route path="backup" element={<BackupManagement />} />
-                      <Route path="cms" element={<CMSPageEnhanced />} />
+                      <Route path="cms" element={<CMSPage />} />
                       <Route index element={<Navigate to="/admin/dashboard" replace />} />
                     </Route>
                   </Route>