dotnet-inspect: use package skills

Discover version-matched package skills, inspect their inventory, and load the ones relevant to the current task. This default workflow is agent-driven and does not change the repository. Persist skills only when the user explicitly asks for repository installation.

Use this workflow to reach the right package-authored skill efficiently. Start by identifying what kind of result the user needs. If the intent or result space is unclear, use a bare target and let the router choose. Otherwise, enter the matching space directly: find <pattern> searches API types/members; package query <exact-id> or package query '<prefix>*' discovers package IDs; and library query <pattern-or-scope> discovers Libraries. Inspect known results with package <exact-id> or library <source>. Unscoped find searches installed .NET Runtime, ASP.NET Core, and .NET Standard platform populations, including Microsoft.Extensions assemblies shipped in the framework populations. Package APIs enter scope through explicit --package, a restored --project, or --package-prefix with a type/member pattern; discover package IDs with package query.