Address review comments

Author: roji

dotnet/src/VectorData/SqliteVec/SqlitePropertyMapping.cs

@@ -62,7 +62,7 @@ public static List<SqliteColumn> GetColumns(IReadOnlyList<IPropertyModel> proper
             else
             {
                 // The Key column in included in both Vector and Data tables.
-                Debug.Assert(property is IKeyPropertyModel, "property is VectorStoreRecordIKeyPropertyModel");
+                Debug.Assert(property is IKeyPropertyModel, "property is not an IKeyPropertyModel");
 
                 propertyType = GetStorageDataPropertyType(property);
                 isPrimary = true;

dotnet/src/VectorData/VectorData.Abstractions/ProviderServices/IPropertyModel.cs

@@ -46,7 +46,7 @@ public interface IPropertyModel
     /// <summary>
     /// Gets a dictionary of provider-specific annotations for this property.
     /// </summary>
-    Dictionary<string, object?>? ProviderAnnotations { get; }
+    IReadOnlyDictionary<string, object?>? ProviderAnnotations { get; }
 
     /// <summary>
     /// Reads the property from the given <paramref name="record"/>, returning the value as an <see cref="object"/>.

dotnet/src/VectorData/VectorData.Abstractions/ProviderServices/KeyPropertyModel.cs

@@ -23,7 +23,6 @@ public class KeyPropertyModel(string modelName, Type type) : PropertyModel(model
     /// (e.g. CosmosDB NoSQL uses "id"): the serializer produces a JSON object with the policy-transformed name, and
     /// the connector needs to find and replace it with the reserved storage name.
     /// </summary>
-    [Experimental("MEVD9001")]
     public string? SerializedKeyName { get; set; }
 
     /// <inheritdoc/>

dotnet/src/VectorData/VectorData.Abstractions/ProviderServices/PropertyModel.cs

@@ -55,6 +55,8 @@ public string StorageName
     /// </remarks>
     public Dictionary<string, object?>? ProviderAnnotations { get; set; }
 
+    IReadOnlyDictionary<string, object?>? IPropertyModel.ProviderAnnotations => this.ProviderAnnotations;
+
     /// <summary>
     /// Gets whether the property type is nullable. For value types, this is <see langword="true"/> when the type is
     /// <see cref="Nullable{T}"/>. For reference types on .NET 6+, this uses NRT annotations via

dotnet/test/VectorData/VectorData.UnitTests/PropertyModelTests.cs

@@ -6,7 +6,7 @@
 
 namespace VectorData.UnitTests;
 
-public class IPropertyModelTests
+public class PropertyModelTests
 {
     #region Value type nullability