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

tests/CBDD.Tests/BsonSpanReaderWriterTests.cs

@@ -9,6 +9,9 @@ public class BsonSpanReaderWriterTests
     private readonly ConcurrentDictionary<string, ushort> _keyMap = new(StringComparer.OrdinalIgnoreCase);
     private readonly ConcurrentDictionary<ushort, string> _keys = new();
 
+    /// <summary>
+    /// Initializes a new instance of the <see cref="BsonSpanReaderWriterTests"/> class.
+    /// </summary>
     public BsonSpanReaderWriterTests()
     {
         ushort id = 1;
@@ -21,6 +24,9 @@ public class BsonSpanReaderWriterTests
         }
     }
 
+    /// <summary>
+    /// Tests write and read simple document.
+    /// </summary>
     [Fact]
     public void WriteAndRead_SimpleDocument()
     {
@@ -65,6 +71,9 @@ public class BsonSpanReaderWriterTests
         value3.ShouldBeTrue();
     }
 
+    /// <summary>
+    /// Tests write and read object id.
+    /// </summary>
     [Fact]
     public void WriteAndRead_ObjectId()
     {
@@ -90,6 +99,9 @@ public class BsonSpanReaderWriterTests
         readOid.ShouldBe(oid);
     }
 
+    /// <summary>
+    /// Tests read write double.
+    /// </summary>
     [Fact]
     public void ReadWrite_Double()
     {
@@ -108,6 +120,9 @@ public class BsonSpanReaderWriterTests
         val.ShouldBe(123.456);
     }
 
+    /// <summary>
+    /// Tests read write decimal128 round trip.
+    /// </summary>
     [Fact]
     public void ReadWrite_Decimal128_RoundTrip()
     {
@@ -127,6 +142,9 @@ public class BsonSpanReaderWriterTests
         val.ShouldBe(original);
     }
 
+    /// <summary>
+    /// Tests write and read date time.
+    /// </summary>
     [Fact]
     public void WriteAndRead_DateTime()
     {
@@ -155,6 +173,9 @@ public class BsonSpanReaderWriterTests
         readTime.ShouldBe(expectedTime);
     }
 
+    /// <summary>
+    /// Tests write and read numeric types.
+    /// </summary>
     [Fact]
     public void WriteAndRead_NumericTypes()
     {
@@ -185,6 +206,9 @@ public class BsonSpanReaderWriterTests
         Math.Round(reader.ReadDouble(), 5).ShouldBe(Math.Round(3.14159, 5));
     }
 
+    /// <summary>
+    /// Tests write and read binary.
+    /// </summary>
     [Fact]
     public void WriteAndRead_Binary()
     {
@@ -211,6 +235,9 @@ public class BsonSpanReaderWriterTests
         testData.AsSpan().SequenceEqual(readData).ShouldBeTrue();
     }
 
+    /// <summary>
+    /// Tests write and read nested document.
+    /// </summary>
     [Fact]
     public void WriteAndRead_NestedDocument()
     {