Refactor code structure and optimize performance across multiple modules

src/__Tests/Graph/StellaOps.Graph.Indexer.Tests/GraphSnapshotBuilderTests.cs

@@ -14,6 +14,7 @@ using StellaOps.Graph.Indexer.Ingestion.Vex;
 using StellaOps.Graph.Indexer.Schema;
 using Xunit;
 
+using StellaOps.TestKit;
 namespace StellaOps.Graph.Indexer.Tests;
 
 public sealed class GraphSnapshotBuilderTests
@@ -21,7 +22,8 @@ public sealed class GraphSnapshotBuilderTests
     private static readonly string FixturesRoot =
         Path.Combine(AppContext.BaseDirectory, "Fixtures", "v1");
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public void Build_creates_manifest_and_adjacency_with_lineage()
     {
         var sbomSnapshot = Load<SbomSnapshot>("sbom-snapshot.json");