docs(sdk): design standardized solution setup

[Copilot]

Ark.Tools consumers currently copy build conventions and analyzer configuration from sample projects, causing configuration drift. This proposes a versioned distribution model for those shared defaults.

• Architecture

  • Compares MSBuild SDK and NuGet buildTransitive approaches.
  • Recommends an additive Ark.Tools.Sdk because it supports conditional package references without leaking policy transitively.

• Current-state inventory

  • Catalogs existing build, analyzer, banned-symbol, packaging, SQL, Reqnroll, and MTP behavior.
  • Proposes inclusion, exclusion, or profile-specific handling for each default.

• External research

  • Evaluates relevant capabilities from Meziantou.NET.Sdk and its deprecated CodingStandard predecessor.
  • Retains MTP findings while excluding framework-specific xUnit/MSTest features.

• Decision record

  • Adds 23 review questions with alternatives and recommendations.
  • Separates stable design documentation from progress and decision material.

[AndreaCuneo]

@copilot update the design based on the answered questions. Improve the details of the one still open and do another feedback round.

[Copilot]

@copilot update the design based on the answered questions. Improve the details of the one still open and do another feedback round.

Updated in eb97110. Accepted answers now drive the stable design; the second feedback round is reduced to four expanded open decisions covering distribution, SDK composition, MTP/framework boundaries, and package-version ownership.

[AndreaCuneo]

@copilot if needed do another feedback round

[Copilot]

@copilot if needed do another feedback round

A third feedback round is needed for one verified hybrid boundary only: SDK-24 asks whether Ark.Tools.Build may flow into packed package dependencies. The design recommends private-by-default with an explicit publication opt-in; public, private, and opt-in modes were all validated in a local restore/pack spike.

[Copilot]

The Initialize containers custom setup step from your .github/workflows/copilot-setup-steps.yml file failed.