Fix audit findings for coverage, architecture checks, and XML docs

tests/CBDD.Tests/VectorMathTests.cs

@@ -4,6 +4,9 @@ namespace ZB.MOM.WW.CBDD.Tests;
 
 public class VectorMathTests
 {
+    /// <summary>
+    /// Verifies distance calculations across all supported vector metrics.
+    /// </summary>
     [Fact]
     public void Distance_Should_Cover_All_Metrics()
     {
@@ -21,6 +24,9 @@ public class VectorMathTests
         MathF.Abs(cosineDistance - expectedCosine).ShouldBeLessThan(0.0001f);
     }
 
+    /// <summary>
+    /// Verifies cosine similarity returns zero when one vector has zero magnitude.
+    /// </summary>
     [Fact]
     public void CosineSimilarity_Should_Return_Zero_For_ZeroMagnitude_Vector()
     {
@@ -30,6 +36,9 @@ public class VectorMathTests
         VectorMath.CosineSimilarity(v1, v2).ShouldBe(0f);
     }
 
+    /// <summary>
+    /// Verifies dot product throws for mismatched vector lengths.
+    /// </summary>
     [Fact]
     public void DotProduct_Should_Throw_For_Length_Mismatch()
     {
@@ -39,6 +48,9 @@ public class VectorMathTests
         Should.Throw<ArgumentException>(() => VectorMath.DotProduct(v1, v2));
     }
 
+    /// <summary>
+    /// Verifies squared Euclidean distance throws for mismatched vector lengths.
+    /// </summary>
     [Fact]
     public void EuclideanDistanceSquared_Should_Throw_For_Length_Mismatch()
     {