Add project files

Converters/EnumEqualsConverter.cs

@@ -0,0 +1,29 @@
+using System;
+using System.Globalization;
+using Avalonia.Data.Converters;
+
+namespace NexvaneHub.Converters;
+
+/// <summary>
+/// Compares a bound enum value's string representation against ConverterParameter.
+/// Used for "is this nav item selected" / "is this section visible" bindings.
+/// </summary>
+public class EnumEqualsConverter : IValueConverter
+{
+    public static readonly EnumEqualsConverter Instance = new();
+
+    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        if (value is null || parameter is null)
+        {
+            return false;
+        }
+
+        return string.Equals(value.ToString(), parameter.ToString(), StringComparison.OrdinalIgnoreCase);
+    }
+
+    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+    {
+        throw new NotSupportedException();
+    }
+}