Use the open-source free `CSharpier` formatter for C# and XML. Use when a .NET repo intentionally wants one opinionated formatter instead of a highly configurable `dotnet format`-driven style model. USE FOR: the repo uses or wants CSharpier; the team prefers an opinionated formatter over many configurable style knobs. DO NOT USE FOR: repos that already standardized on dotnet format as the only formatter. INVOKES: inspect the repository context, edit targeted files, and run relevant build, test, lint, or validation commands when changes are made.