Add support for Service Fabric .sfproj config project in .slnx solution file #12112
Description
Summary
Support for including sfproj (Service Fabric configuration projects) in .slnx solution files. Currently, these project types are not loaded when opening .slnx files, making the new format unusable for solutions containing Service Fabric components.
Related:
#10266
Background and Motivation
Our organization manages dozens of large Visual Studio solutions, many of which contain hundreds of projects. Among them, we heavily use Service Fabric, with each solution typically including at least one sfproj configuration project alongside other .NET projects.
Due to the sheer size of .sln files and the complexity of merging them in source control, we were excited about the introduction of the .slnx format as a cleaner, more structured alternative. However, while experimenting with .slnx, we discovered that sfproj files are not being loaded when included in the .slnx file. Either there is no way to represent these project types yet, or they are simply unsupported.
This limitation makes .slnx impractical for our usage scenarios and blocks adoption.
Proposed Feature
Ensure that .slnx format fully supports sfproj files, allowing them to be included, parsed, and loaded into Visual Studio or any tooling that works with .slnx. Ideally, the .slnx schema should include an example or documentation entry showing how to correctly include sfproj and related project types.
If .slnx is intended to replace .sln in large-scale enterprise scenarios, supporting Service Fabric (which is still actively used in many enterprises) is essential.
Alternative Designs
No response