Prevent Cross-Solution Configuration Propagation During Merge

[Vladnee]

Hello,

First of all, thank you for this excellent plugin — it perfectly fits my workflow and solves a real problem for me.

However, I have encountered an issue when merging a Unity client solution with a backend solution.

After the merge, all projects end up having all configurations that exist across both solutions. In other words, if one solution has configurations like Debug and Release, and another has Server-dev and Server-prod, then every project in the merged solution receives all of these configurations.

This leads to situations where:

• Unity projects receive server-only configurations
• Backend projects receive Unity-specific configurations
• The .sln file contains unnecessary project configuration entries

It would be extremely helpful to have an option that restricts project configurations in the merged solution to only those explicitly defined in each project's .csproj file.

For example:

• If a project defines Server-dev;Server-prod;, only those configurations should appear in ProjectConfigurationPlatforms for that project.
• If a project defines only a default Debug, then only Debug should be present for that project.

This would keep the merged solution clean and deterministic, especially when combining heterogeneous solutions like Unity and ASP.NET backend projects.

Would it be possible to add such an option (e.g., "PruneProjectConfigurationsByCsproj")?

Thank you again for the great tool.