migrate-dotnet10-to-dotnet11

# .NET 10 → .NET 11 Migration Migrate a .NET 10 project or solution to .NET 11, systematically resolving all breaking changes. The outcome is a project targeting `net11.0` that builds cleanly, passes tests, and accounts for every behavioral, source-incompatible, and binary-incompatible change introduced in .NET 11. > **Note:** .NET 11 is currently in preview. This skill covers breaking changes documented through Preview 1. It will be updated as additional previews ship. ## When to Use - Upgrading `TargetFramework` from `net10.0` to `net11.0` - Resolving build errors or new warnings after updating the .NET 11 SDK - Adapting to behavioral changes in .NET 11 runtime, ASP.NET Core 11, or EF Core 11 - Updating CI/CD pipelines, Dockerfiles, or deployment scripts for .NET 11 - Fixing C# 15 compiler breaking changes after SDK upgrade ## When Not to Use - The project already targets `net11.0` and builds cleanly — migration is done - Upgrading from .NET 9 or earlier — address the .NET 9→10 breaking changes first - Migrating from .NET Framework — that is a separate, larger effort - Greenfield projects that start on .NET 11 (no migration needed) ## Inputs | Input | Required | Description | |-------|----------|-------------| | Project or solution path | Yes | The `.csproj`, `.sln`, or `.slnx` entry point to migrate | | Build command | No | How to build (e.g., `dotnet build`, a repo build script). Auto-detect if not provided | | Test command | No | How to run tests (e.g., `dotnet t...