Implement AirPrint/IPP Everywhere printing feature

[Copilot]

This PR adds printing functionality to ScanBridge using Android's Print Framework, enabling users to print scanned documents directly to AirPrint and IPP Everywhere compatible printers.

Changes

UI Enhancement

• Added a print button (🖨️) to the export options popup alongside the existing PDF and Archive export buttons
• The print option appears when users tap the share/export button in the scanning screen

Core Implementation

• doPrint() function: Integrates with Android's PrintManager to handle print jobs
• ScanDocumentPrintAdapter class: Custom PrintDocumentAdapter that converts scanned images to PDF format for printing
• Error handling: Same validation as existing export functions (checks for empty scans, running jobs, etc.)

Internationalization

• Added "Print" string resources in both English and German translations

Technical Details

The implementation leverages Android's Print Framework which automatically discovers and supports:

• AirPrint printers (Apple ecosystem)
• IPP Everywhere printers
• Any printer with Android print service support

User Experience

When printing, users get the full Android system print dialog with options to:

• Select from available printers
• Choose page ranges
• Adjust print settings (paper size, orientation, etc.)
• Preview before printing

Key Features

• Multi-page support: Prints all scanned pages as a single job
• Page range selection: Users can print specific pages through the system dialog
• Automatic scaling: Images are scaled to fit A4 pages with proper margins
• Cancellation support: Users can cancel print jobs in progress

Compatibility

• Maintains backward compatibility with existing export functionality
• Works with Android 28+ (existing app requirement)
• No additional permissions required
• Uses existing iText PDF library for document generation

The implementation follows existing app patterns and provides a seamless printing experience for scanned documents without modifying any core scanning functionality.

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