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/AwsKmsOptions.cs

@@ -0,0 +1,54 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace StellaOps.Cryptography.Kms;
+
+/// <summary>
+/// Configuration for the AWS KMS-backed <see cref="IKmsClient"/>.
+/// </summary>
+public sealed class AwsKmsOptions
+{
+    private TimeSpan metadataCacheDuration = TimeSpan.FromMinutes(5);
+    private TimeSpan publicKeyCacheDuration = TimeSpan.FromMinutes(10);
+
+    /// <summary>
+    /// Gets or sets the AWS region identifier (e.g. <c>us-east-1</c>).
+    /// </summary>
+    public string Region { get; set; } = "us-east-1";
+
+    /// <summary>
+    /// Gets or sets an optional custom service endpoint (useful for local stacks or VPC endpoints).
+    /// </summary>
+    public string? Endpoint { get; set; }
+
+    /// <summary>
+    /// Gets or sets a value indicating whether to use the FIPS endpoint for AWS KMS.
+    /// </summary>
+    public bool UseFipsEndpoint { get; set; }
+
+    /// <summary>
+    /// Gets or sets the cache duration for key metadata lookups.
+    /// </summary>
+    public TimeSpan MetadataCacheDuration
+    {
+        get => metadataCacheDuration;
+        set => metadataCacheDuration = EnsurePositive(value, TimeSpan.FromMinutes(5));
+    }
+
+    /// <summary>
+    /// Gets or sets the cache duration for exported public key material.
+    /// </summary>
+    public TimeSpan PublicKeyCacheDuration
+    {
+        get => publicKeyCacheDuration;
+        set => publicKeyCacheDuration = EnsurePositive(value, TimeSpan.FromMinutes(10));
+    }
+
+    /// <summary>
+    /// Gets or sets an optional factory that can provide a custom AWS facade. Primarily used for testing.
+    /// </summary>
+    public Func<IServiceProvider, IAwsKmsFacade>? FacadeFactory { get; set; }
+
+    private static TimeSpan EnsurePositive(TimeSpan value, TimeSpan @default)
+        => value <= TimeSpan.Zero ? @default : value;
+}
+