Extend native DSC v3 resources in WinGet Client (PackageList, Pin, and installer type)

Relevant area(s)

• DSC Resource
• WinGet CLI

Description of the new feature / enhancement

Extend the native DSC v3 command resources shipped with the WinGet client to cover package-set
convergence and package pins while improving package installer selection.

WinGet already provides these native resources:

• Microsoft.WinGet/Package
• Microsoft.WinGet/Source
• Microsoft.WinGet/UserSettingsFile
• Microsoft.WinGet/AdminSettings

The remaining enhancements are:

• Add an optional per-package installerType requirement to package resources.
• Add Microsoft.WinGet/PackageList for declaring a package set with guarded DSC _purge
  semantics.
• Add Microsoft.WinGet/Pin for declarative package pin management.
• Export WinGet Configuration files using native resources.

Native command resources avoid the PowerShell adapter overhead required by the
Microsoft.WinGet.DSC class-based resources.

Proposed technical implementation details

Users author, test, and apply the resources through winget configure. The existing winget dsc
alias remains equivalent to winget configure.

The implementation-facing winget dscv3 commands continue to implement the DSC command-resource
protocol used by the resource manifests:

• winget dscv3 <resource> --get
• winget dscv3 <resource> --set
• winget dscv3 <resource> --test
• winget dscv3 <resource> --export
• winget dscv3 <resource> --schema
• winget dscv3 <resource> --manifest

Microsoft.WinGet/PackageList should:

• accept package-specific source, version, installer type, install mode, and agreement settings
• treat installerType as a requirement when specified
• support opt-in _purge behavior that defaults to false
• remove only packages WinGet can establish were authoritatively managed by WinGet
• never remove unknown, best-effort-correlated, protected, or unsupported Windows software
• require an enabling Group Policy before processing _purge: true

Microsoft.WinGet/Pin should manage one pin per resource instance and use DSC _exist for removal.

Specification: https://github.com/microsoft/winget-cli/pull/6291

Start with the specification in pull request 6291 and the existing winget dscv3 <resource> command-resource protocol. Review the Package, PackageList, and Pin resource behavior described here, including installer requirements, guarded _purge, and _exist removal. Done means the resources support get, set, test, export, schema, and manifest through winget configure with the stated safety rules.