Design

Problem

Cross-repo libraries need one committed declaration that works for:

• Local multi-repo iteration — compile against sibling source when the project is checked out
• CI / single-repo consumers — restore from NuGet when the sibling project is absent

Novolis historically keeps committed PackageReference only and optionally rewrites to ProjectReference in ProjectReference mode. LibraryReference inverts that: the committed item is the dependency; expansion chooses project vs package at evaluation time (required for NuGet restore; a Target-added ProjectReference fails with NETSDK1004).

Resolution

LibraryReference (PackageId, optional Version, optional ProjectPath)
  → stamp ProjectPath from LibraryProjectMap when missing
  → if ProjectPath exists and is not self → ProjectReference (+ forwarded metadata)
  → else → PackageReference (Version or LibraryReferenceDefaultVersion)
       CPM: also PackageVersion when no central row exists yet

No filesystem crawl. Paths come from explicit metadata or LibraryProjectMap (same reliability model as the generated NovolisPackageProject map).

Packaging

Props/targets-only NuGet package (IncludeBuildOutput=false, DevelopmentDependency=true). Auto-imported from build/ and buildTransitive/ when referenced.

Non-goals (this repo)

• Migrating every existing Novolis PackageReference to LibraryReference (governance already imports these targets for any project that declares the item)
• Inventing transitive ProjectReferences for NuGet dependency graphs