Create comprehensive project structure and setup tools for FinTrackForWindows

[Copilot]

This PR establishes a proper project structure and development environment for the FinTrackForWindows repository. The changes provide developers with automated setup tools and clear documentation to get started quickly.

Changes Made

Project Organization

• Added root-level solution file (FinTrackForWindows.sln) that properly references the existing project in the FinTrack/ subdirectory
• Created project metadata (project.json) containing comprehensive project information, requirements, and available scripts

Developer Experience

• Automated setup scripts for both Windows (setup.bat) and Unix (setup.sh) environments that:
  • Verify .NET 8.0 SDK installation
  • Restore NuGet packages automatically
  • Attempt to build the project with proper error handling
  • Provide clear feedback and next steps
• Comprehensive development guide (DEVELOPMENT.md) covering:
  • Project architecture and MVVM pattern
  • Development workflow and best practices
  • Troubleshooting common issues
  • Contribution guidelines

Documentation Updates

• Updated README.md with corrected installation instructions that reference the new setup scripts and proper solution file location

Benefits

1. Streamlined onboarding - New developers can run a single script to verify their environment and get started
2. Better project organization - Root-level solution file provides cleaner repository structure
3. Clear documentation - Comprehensive guides reduce confusion and improve development efficiency
4. Cross-platform awareness - Setup scripts properly handle Windows-specific WPF requirements and explain limitations on other platforms

Testing

The setup scripts have been tested and properly handle:

• ✅ .NET SDK detection and version reporting
• ✅ Package restoration with appropriate warnings for cross-platform packages
• ✅ Expected build failures on non-Windows platforms (due to WPF dependencies)
• ✅ Clear messaging about Windows/Visual Studio requirements

The root solution file correctly references the existing project and works with standard .NET CLI commands like dotnet sln list.

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