Fix double MyClass prefix when converting MyClass._Prop backing field access

When _Prop is accessed via MyClass._Prop, NameExpressionNodeVisitor.cs
already adds the MyClass prefix via "$MyClass{ConvertIdentifier(...).ValueText}".
The new ConvertIdentifier code was also returning MyClassProp for _Prop,
causing a double prefix MyClassMyClassProp.

Fix: detect when _Prop is part of a MyClass._Prop member access and
return the bare property name so NameExpressionNodeVisitor can prefix it.

https://claude.ai/code/session_01AkwUvu3XuCdj3D4axoX4UX

Author: claude

CodeConverter/CSharp/CommonConversions.cs

@@ -293,8 +293,10 @@ public SyntaxToken ConvertIdentifier(SyntaxToken id, bool isAttribute = false, S
                     // AND the first explicitly declared parameter is this symbol, we need to replace it with value.
                     text = "value";
                 } else if (normalizedText.StartsWith("_", StringComparison.OrdinalIgnoreCase) && idSymbol is IFieldSymbol propertyFieldSymbol && propertyFieldSymbol.AssociatedSymbol?.IsKind(SymbolKind.Property) == true) {
-                    // For virtual auto-properties, VB backing field _Prop maps to the C# MyClassProp backing property (bypasses virtual dispatch)
-                    text = propertyFieldSymbol.IsImplicitlyDeclared && propertyFieldSymbol.AssociatedSymbol is IPropertySymbol { IsVirtual: true, IsAbstract: false } vProp
+                    // For virtual auto-properties, VB backing field _Prop maps to the C# MyClassProp backing property (bypasses virtual dispatch).
+                    // Exception: when accessed as MyClass._Prop, NameExpressionNodeVisitor adds the "MyClass" prefix itself, so we just return the property name.
+                    var isAccessedViaMyClass = id.Parent?.Parent is VBSyntax.MemberAccessExpressionSyntax { Expression: VBSyntax.MyClassExpressionSyntax };
+                    text = !isAccessedViaMyClass && propertyFieldSymbol.IsImplicitlyDeclared && propertyFieldSymbol.AssociatedSymbol is IPropertySymbol { IsVirtual: true, IsAbstract: false } vProp
                         ? "MyClass" + vProp.Name
                         : propertyFieldSymbol.AssociatedSymbol.Name;
                 } else if (normalizedText.EndsWith("Event", StringComparison.OrdinalIgnoreCase) && idSymbol is IFieldSymbol eventFieldSymbol && eventFieldSymbol.AssociatedSymbol?.IsKind(SymbolKind.Event) == true) {