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

backend/src/routes/adminSystem.js

@@ -1,6 +1,6 @@
 const express = require('express');
 const { db, withRetry } = require('../database/db');
-const { adminAuth } = require('../middleware/auth-enhanced-v2');
+const { adminAuth } = require('../middleware/auth');
 const fs = require('fs').promises;
 const path = require('path');
 const os = require('os');