Fix file dialog crashes and add console application

[temotskipa]

Problem Fixed

The GDeflate Compressor GUI application was crashing when users tried to add files or folders due to insufficient error handling around file dialog operations.

Changes Made

🛠️ Enhanced Error Handling in GUI Application

• Added comprehensive try-catch blocks around OpenFileDialog and FolderBrowserDialog operations
• Enhanced btnAddFiles_Click(), btnAddFolder_Click(), and btnDecompress_Click() methods with robust error handling
• Improved user feedback with clear error messages and status updates
• Added graceful error recovery for batch operations - users can choose to continue when individual files fail

🆕 New Console Application (GDeflateConsole)

• Created cross-platform command-line interface for compression operations
• Supports compress, decompress, and list commands
• Works on Windows, Linux, and macOS
• Includes simulation mode for testing on platforms without CUDA support
• Useful for automation, scripting, and testing

📚 Documentation Updates

• Updated README.md with comprehensive usage instructions for both applications
• Added build instructions for the console application
• Documented recent improvements and features
• Enhanced .gitignore to exclude .NET build artifacts

Usage Examples

Console Application

# Compress a file
dotnet run --project GDeflateConsole compress document.pdf

# Decompress a file  
dotnet run --project GDeflateConsole decompress document.pdf.gdef

# List files in directory
dotnet run --project GDeflateConsole list /path/to/files

Testing

• ✅ GUI application builds successfully with enhanced error handling
• ✅ Console application builds and runs on multiple platforms
• ✅ Error handling prevents crashes when dialogs fail
• ✅ User receives clear feedback when operations encounter issues
• ✅ Batch operations continue gracefully when individual files fail

Benefits

• Stability: No more crashes when adding files/folders
• User Experience: Clear error messages guide users to resolve issues
• Cross-Platform: Console application works on any .NET-supported platform
• Automation: Command-line interface enables scripting and automated workflows
• Testing: Console app allows testing core functionality without GUI dependencies

This PR resolves the crash issue while maintaining full backward compatibility and adding valuable new functionality.

@temotskipa can click here to continue refining the PR