dotnet
dotnet (skill router)
The single source-of-truth index mapping a concrete .NET work area - a construct, command, file, or task - to the one focused skill to load. It routes, it does not restate: load the named skill for the actual guidance. Pick by what you are about to do; if several rows match, load several.
Companion, not optional: load csharp whenever you write or refactor any C# - naming, layout, modern syntax, async, dispose, exceptions/Result, logging, DI lifetimes. Every row below is in addition to the C# baseline, never instead of it.
Required vs optional. The always-on spine of any .NET work is three skills: this router, csharp (every .cs file), and dotnet-testing (the moment a test is written or changed - tests are part of the done gate). Add exactly one surface hub for the app under build - dotnet-web-backend (ASP.NET Core), dotnet-console-apps + dotnet-hosted-services (worker / CLI / bot / daemon), or dotnet-wpf / dotnet-winforms (desktop). Every other row below is an optional specialist, loaded only when its area is in play - never up front.
The trigger is the artifact, not 'am I doing .NET'. In a specific repo, that repo's CLAUDE.md binds these rows to its own file names and folders.