Refactor code structure and optimize performance across multiple modules

src/Scanner/__Tests/StellaOps.Scanner.Reachability.Tests/SubgraphExtractorTests.cs

@@ -6,6 +6,7 @@ using StellaOps.Scanner.Reachability;
 using StellaOps.Scanner.Reachability.Models;
 using Xunit;
 
+using StellaOps.TestKit;
 namespace StellaOps.Scanner.Reachability.Tests;
 
 /// <summary>
@@ -33,7 +34,8 @@ public class SubgraphExtractorTests
         );
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task ResolveAsync_WithSinglePath_ReturnsCorrectSubgraph()
     {
         // Arrange
@@ -75,7 +77,8 @@ public class SubgraphExtractorTests
         Assert.True(result.Edges.Count > 0);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task ResolveAsync_NoReachablePath_ReturnsNull()
     {
         // Arrange
@@ -113,7 +116,8 @@ public class SubgraphExtractorTests
         Assert.Null(result);
     }
 
-    [Fact]
+    [Trait("Category", TestCategories.Unit)]
+        [Fact]
     public async Task ResolveAsync_DeterministicOrdering_ProducesSameHash()
     {
         // Arrange