migrate-vstest-to-mtp

# VSTest -> Microsoft.Testing.Platform Migration Migrate a .NET test solution from VSTest to Microsoft.Testing.Platform (MTP). The outcome is a solution where all test projects run on MTP, `dotnet test` works correctly, and CI/CD pipelines are updated. > **Important**: Do not mix VSTest-based and MTP-based .NET test projects in the same solution or run configuration -- this is an unsupported scenario. ## When to Use - Switching from VSTest to Microsoft.Testing.Platform for any supported test framework - Enabling `dotnet run` / `dotnet watch` / direct executable execution for test projects - Enabling Native AOT or trimmed test execution - Replacing `vstest.console.exe` with `dotnet test` on MTP - Updating CI/CD pipelines from the VSTest task to the .NET Core CLI task - Updating `dotnet test` arguments from VSTest syntax to MTP syntax ## When Not to Use - The project already runs on Microsoft.Testing.Platform -- migration is done - Migrating between test frameworks (e.g., MSTest to xUnit.net) -- different effort entirely - The project builds UWP or packaged WinUI test projects -- MTP does not support these yet - The solution mixes .NET and non-.NET test adapters (e.g., JavaScript or C++ adapters) -- VSTest is required - Upgrading MSTest versions -- use `migrate-mstest-v1v2-to-v3` or `migrate-mstest-v3-to-v4` ## Inputs | Input | Required | Description | |-------|----------|-------------| | Project or solution path | Yes | The `.csproj`, `.sln`, or `.slnx` entry point con...