The issue requests the ability to rename nested partial class files in the Visual Studio IDE. To implement this, one must understand how Visual Studio handles file renaming for partial classes, likely involving the Roslyn workspace API and project system. Investigate the current renaming logic for non partial files in the Roslyn repository, such as the `IFileRenameService` or related components. Also, examine how the `.csproj` file is updated when renaming files, as the issue mentions manual editing of the project file.
