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

tests/CBDD.Tests/GeospatialStressTests.cs

@@ -7,12 +7,18 @@ public class GeospatialStressTests : IDisposable
     private readonly string _dbPath;
     private readonly Shared.TestDbContext _db;
 
+    /// <summary>
+    /// Initializes database state for geospatial stress tests.
+    /// </summary>
     public GeospatialStressTests()
     {
         _dbPath = Path.Combine(Path.GetTempPath(), $"geo_stress_{Guid.NewGuid():N}.db");
         _db = new Shared.TestDbContext(_dbPath);
     }
 
+    /// <summary>
+    /// Verifies spatial index handles node splits and query operations under load.
+    /// </summary>
     [Fact]
     public void SpatialIndex_Should_Handle_Node_Splits_And_Queries()
     {
@@ -40,6 +46,9 @@ public class GeospatialStressTests : IDisposable
         near.Count.ShouldBeGreaterThan(0);
     }
 
+    /// <summary>
+    /// Disposes test resources and removes generated files.
+    /// </summary>
     public void Dispose()
     {
         _db.Dispose();