feat: implement comprehensive backup and restore system with S3 support

- Add S3/MinIO storage adapter with multipart upload support
- Implement database backup service for SQLite and PostgreSQL
- Create backup manifest generator for tracking backup contents
- Enhance backup service with S3 integration and incremental backups
- Add restore service with safety measures and rollback capability
- Create comprehensive test suite for all backup functionality
- Add admin API endpoints for backup/restore management
- Implement frontend UI with dashboard, configuration, and restore wizard
- Add roadmap section to README with implemented backup feature

This implementation provides:
- Multiple backup destinations (local, rsync, S3/MinIO)
- Intelligent change detection to minimize backup frequency
- Full database backups with compression
- Manifest-based restore with integrity validation
- Pre-restore safety backups with rollback
- Comprehensive error handling and monitoring
- User-friendly admin interface

🤖 Generated with Claude Code

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

backend/server.js

@@ -20,6 +20,8 @@ const { initializeDatabase, db } = require('./src/database/db');
 const { startFileWatcher } = require('./src/services/fileWatcher');
 const { startExpirationChecker } = require('./src/services/expirationChecker');
 const { initializeTransporter, startEmailQueueProcessor } = require('./src/services/emailProcessor');
+const { startBackupService } = require('./src/services/backupService');
+const { startScheduledBackups } = require('./src/services/databaseBackup');
 const { maintenanceMiddleware } = require('./src/middleware/maintenance');
 const { sessionTimeoutMiddleware } = require('./src/middleware/sessionTimeout');
 const { createRateLimiter, createAuthRateLimiter } = require('./src/services/rateLimitService');
@@ -201,6 +203,8 @@ app.use('/api/gallery', galleryRoutes);
 app.use('/api/admin', adminRoutes);
 app.use('/api/admin/auth', adminAuthRoutes);
 app.use('/api/admin/system', require('./src/routes/adminSystem'));
+app.use('/api/admin/backup', require('./src/routes/adminBackup'));
+app.use('/api/admin/database-backup', require('./src/routes/adminDatabaseBackup'));
 app.use('/api/public/settings', require('./src/routes/publicSettings'));
 app.use('/api/public', require('./src/routes/publicCMS'));
 app.use('/api/images', require('./src/routes/protectedImages'));
@@ -243,6 +247,12 @@ async function startServer() {
     await initializeTransporter();
     startEmailQueueProcessor();
     
+    // Start backup service
+    await startBackupService();
+    
+    // Start database backup service
+    await startScheduledBackups();
+    
     app.listen(PORT, () => {
       logger.info(`Server running on port ${PORT}`);
       logger.info(`Admin interface: ${process.env.ADMIN_URL || 'http://localhost:3000'}`);