feat: Major system improvements and production deployment

✨ New Features:
- Added view_orders route with proper table display
- Implemented CSV upload with preview workflow and date parsing
- Added production WSGI server configuration with Gunicorn
- Created comprehensive production management scripts

🔧 Bug Fixes:
- Fixed upload_data route column mapping for actual CSV structure
- Resolved print module database queries and template rendering
- Fixed view orders navigation routing (was pointing to JSON API)
- Corrected barcode display width constraints in print module
- Added proper date format parsing for MySQL compatibility

🎨 UI/UX Improvements:
- Updated view_orders template with theme-compliant styling
- Hidden barcode text in print module preview for cleaner display
- Enhanced CSV upload with two-step preview-then-save workflow
- Improved error handling and debugging throughout upload process

🚀 Production Infrastructure:
- Added Gunicorn WSGI server with proper configuration
- Created systemd service for production deployment
- Implemented production management scripts (start/stop/status)
- Added comprehensive logging setup
- Updated requirements.txt with production dependencies

📊 Database & Data:
- Enhanced order_for_labels table compatibility
- Fixed column mappings for real CSV data structure
- Added proper date parsing and validation
- Improved error handling with detailed debugging

🔧 Technical Debt:
- Reorganized database setup documentation
- Added proper error handling throughout upload workflow
- Enhanced debugging capabilities for troubleshooting
- Improved code organization and documentation

py_app/app/templates/main_page_etichete.html

@@ -15,7 +15,7 @@
             <p>Upload new orders or view existing orders and manage label data for printing.</p>
             <div style="display: flex; gap: 10px; flex-wrap: wrap;">
                 <a href="{{ url_for('main.upload_data') }}" class="btn">Upload Orders</a>
-                <a href="{{ url_for('main.get_unprinted_orders') }}" class="btn">View Orders</a>
+                <a href="{{ url_for('main.view_orders') }}" class="btn">View Orders</a>
             </div>
         </div>