🔄 Add Comprehensive Backup Management System

✨ New Features:
- Complete backup lifecycle management (create, list, download, delete, cleanup)
- Web-based backup interface with real-time status updates
- Individual backup deletion and bulk cleanup for old backups
- Docker-aware backup operations with volume persistence
- Automated backup scheduling and retention policies

📁 Added Files:
- backup.py - Core backup script for creating timestamped archives
- docker_backup.sh - Docker-compatible backup wrapper script
- app/templates/backup.html - Web interface for backup management
- BACKUP_SYSTEM.md - Comprehensive backup system documentation
- BACKUP_GUIDE.md - Quick reference guide for backup operations

🔧 Enhanced Files:
- Dockerfile - Added backup.py copy for container availability
- docker-compose.yml - Added backup volume mount for persistence
- app/routes/api.py - Added backup API endpoints (create, list, delete, cleanup)
- app/routes/main.py - Added backup management route
- app/templates/index.html - Added backup management navigation
- README.md - Updated with backup system overview and quick start

🎯 Key Improvements:
- Fixed backup creation errors in Docker environment
- Added Docker-aware path detection for container operations
- Implemented proper error handling and user confirmation dialogs
- Added real-time backup status updates via JavaScript
- Enhanced data persistence with volume mounting

💡 Use Cases:
- Data protection and disaster recovery
- Environment migration and cloning
- Development data management
- Automated maintenance workflows

README.md

@@ -11,6 +11,11 @@ A modern Flask web application for generating and managing QR codes with authent
 - **Customizable Styling**: Different QR code styles (square, rounded, circle)
 - **Logo Integration**: Add custom logos to QR codes
 - **Click Tracking**: Monitor short URL usage and statistics
+- **🆕 Comprehensive Backup System**: Full backup lifecycle management
+  - Create backups on-demand or automated
+  - Download, delete, and cleanup old backups
+  - Web-based backup management interface
+  - Docker-aware backup operations
 - **Docker Deployment**: Production-ready containerization
 - **Responsive Design**: Modern web interface that works on all devices
 
@@ -493,6 +498,60 @@ curl http://localhost:5000/health
 
 This project is licensed under the MIT License - see the LICENSE file for details.
 
+## 💾 Backup & Restore System
+
+The QR Code Manager includes a comprehensive backup system for data protection and migration.
+
+### Quick Start
+
+**Create Backup:**
+- Via Web: Navigate to backup management page → "Create Backup"
+- Via API: `curl -X POST http://localhost:8066/api/backup/create`
+- Via CLI: `python backup.py` or `./docker_backup.sh`
+
+**Manage Backups:**
+- **List**: View all backups with timestamps and sizes
+- **Download**: Get backup files directly from web interface
+- **Delete**: Remove individual backups with confirmation
+- **Cleanup**: Bulk remove backups older than 7 days
+
+### What Gets Backed Up
+
+Each backup includes:
+- ✅ All QR code data and metadata
+- ✅ Short URL database
+- ✅ Dynamic link page configurations  
+- ✅ Generated QR code images
+- ✅ Application settings
+
+### Restore Process
+
+```bash
+# 1. Stop application
+docker compose down
+
+# 2. Extract backup to data directory
+cd data/
+unzip ../backups/backup_20250801_143022.zip
+
+# 3. Restart application
+docker compose up -d
+```
+
+### Automated Backups
+
+**Daily Backup (2 AM):**
+```bash
+0 2 * * * cd /opt/qr-code_manager && ./docker_backup.sh
+```
+
+**Weekly Cleanup:**
+```bash
+0 3 * * 0 curl -X POST http://localhost:8066/api/backup/cleanup
+```
+
+> 📖 **Detailed Documentation**: See [BACKUP_SYSTEM.md](BACKUP_SYSTEM.md) for complete backup system documentation.
+
 ## 🤝 Contributing
 
 1. Fork the repository