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

tests/CBDD.Tests/StorageEngineDictionaryTests.cs

@@ -13,6 +13,9 @@ public class StorageEngineDictionaryTests
         if (File.Exists(Path.ChangeExtension(path, ".wal"))) File.Delete(Path.ChangeExtension(path, ".wal"));
     }
 
+    /// <summary>
+    /// Verifies dictionary pages are initialized and return normalized keys.
+    /// </summary>
     [Fact]
     public void StorageEngine_ShouldInitializeDictionary()
     {
@@ -32,6 +35,9 @@ public class StorageEngineDictionaryTests
         finally { Cleanup(path); }
     }
 
+    /// <summary>
+    /// Verifies dictionary entries persist across reopen.
+    /// </summary>
     [Fact]
     public void StorageEngine_ShouldPersistDictionary()
     {
@@ -61,6 +67,9 @@ public class StorageEngineDictionaryTests
         finally { Cleanup(path); }
     }
 
+    /// <summary>
+    /// Verifies dictionary handling scales to many keys and remains durable.
+    /// </summary>
     [Fact]
     public void StorageEngine_ShouldHandleManyKeys()
     {