[LukasNiessen]

The promoted .NET implementation has no consumable NuGet release, metric rule assertions throw while formatting valid violations, and trailing /** folder selectors can omit direct children. This PR prepares the complete package graph and fixes those two behavior defects.

Changes:

• Format all five metric violation families through the generic and xUnit assertion paths, preserving measured values, comparisons, predicate messages, subjects and zone coordinates. Add the required acyclic Testing → Metrics dependency and update its dogfood constraint.
• Include the base folder when a glob ends in /**, with a regression where a direct-child violation was previously missed despite a nonempty nested selection.
• Prepare all 11 .NET 10 packages at the proposed coordinated version 3.0.0-beta.1: root NuGet ID ArchUnit, supporting IDs ArchUnitSharp.*, existing assemblies/namespaces retained. Include repository metadata, original-author attribution, README and XML documentation.
• Inspect package identities and the complete internal dependency graph, then restore/test a consumer outside the checkout using a fresh cache and package-source mapping. Exercise dependency, cycle and LOC fail/fix/pass scenarios plus layers/slices/graph examples.
• Add package-consumer CI on Linux, Windows and macOS, a manual prepare/publish workflow, and migration/release documentation with explicit legacy-feature status.

Validation on macOS ARM64 with .NET SDK 10.0.403:

• Release build: zero warnings/errors.
• All 12 test suites pass: 1,882 tests, no skips. The explicit dogfood dependency table was updated after it correctly rejected the newly required Testing → Metrics edge; its six tests then passed.
• dotnet format --verify-no-changes.
• All 11 packages built and inspected; the fresh external consumer passed all four tests.
• Publication guard correctly rejects the current artifacts because the promoted implementation has no confirmed license.
• actionlint and git diff --check pass.

Release decisions still open under #53:

• Review the proposed IDs/version and confirm license provenance with the implementation owner. Neither repository currently declares a recognized license; this PR deliberately does not reuse the legacy package’s license. Publication requires a reviewed root LICENSE included in every artifact.
• Configure the NuGet environment/publishing rights, publish only after review, and verify public installation. No packages were published by this PR preparation.
• Coordinate website changes after publication and the former repository owner’s redirect/retirement.

This does not expand the documented local-using dependency model (#47) or claim to resolve all selector compatibility differences in #54.

Fixes #51.
Refs #53 and #54.