Add unit tests for SBOM ingestion and transformation

- Implement `SbomIngestServiceCollectionExtensionsTests` to verify the SBOM ingestion pipeline exports snapshots correctly.
- Create `SbomIngestTransformerTests` to ensure the transformation produces expected nodes and edges, including deduplication of license nodes and normalization of timestamps.
- Add `SbomSnapshotExporterTests` to test the export functionality for manifest, adjacency, nodes, and edges.
- Introduce `VexOverlayTransformerTests` to validate the transformation of VEX nodes and edges.
- Set up project file for the test project with necessary dependencies and configurations.
- Include JSON fixture files for testing purposes.

src/__Libraries/StellaOps.Cryptography.Kms/IFido2Authenticator.cs

@@ -0,0 +1,17 @@
+namespace StellaOps.Cryptography.Kms;
+
+/// <summary>
+/// Represents a FIDO2 authenticator capable of producing signatures over digests.
+/// </summary>
+public interface IFido2Authenticator
+{
+    /// <summary>
+    /// Performs a high-assurance signing operation using the configured FIDO2 credential.
+    /// </summary>
+    /// <param name="credentialId">Credential identifier as configured in the relying party.</param>
+    /// <param name="digest">Digest of the payload (typically SHA-256) to sign.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>Signature bytes.</returns>
+    Task<byte[]> SignAsync(string credentialId, ReadOnlyMemory<byte> digest, CancellationToken cancellationToken = default);
+}
+