feat: implement critical security fixes for SQL injection and authentication vulnerabilities

Security Enhancements:
- Fix SQL injection vulnerabilities by replacing whereRaw queries with parameterized queries
- Add LIKE pattern escaping to prevent SQL injection in search functionality
- Implement account lockout protection (5 failed attempts = 30 min lockout)
- Add comprehensive login attempt tracking and audit trail
- Enhance JWT tokens with issuer validation, IP tracking, and password change detection
- Add logout endpoint and session management
- Prevent user enumeration with generic error messages

Database Changes:
- Add login_attempts table for authentication tracking
- Add security columns to admin_users (password_changed_at, last_login_ip, two_factor_enabled)

New Security Features:
- Brute force protection with configurable lockout duration
- Automatic cleanup of old login attempts
- Enhanced authentication middleware with stricter validation
- Monitoring scripts for security health checks

All fixes are backward compatible and production-ready with rollback plans included.

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

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

backend/server.js

@@ -19,7 +19,7 @@ const { sessionTimeoutMiddleware } = require('./src/middleware/sessionTimeout');
 const logger = require('./src/utils/logger');
 
 // Import routes
-const authRoutes = require('./src/routes/auth');
+const authRoutes = require('./src/routes/auth-enhanced');
 const eventRoutes = require('./src/routes/events');
 const galleryRoutes = require('./src/routes/gallery');
 const adminRoutes = require('./src/routes/admin');
@@ -141,6 +141,10 @@ async function startServer() {
   try {
     // Initialize database
     await initializeDatabase();
+
+  // Initialize auth security cleanup job
+  const { initializeCleanupJob } = require('./src/utils/authSecurity');
+  initializeCleanupJob();
     
     // Start file watcher
     startFileWatcher();