Add project reference for TeleWave.Infrastructure: include TeleWave.Infrastructure.csproj in TeleWave.Application.Tests project to support additional testing capabilities.

backend/tests/TeleWave.Domain.Tests/Images/ImageTests.cs

@@ -0,0 +1,28 @@
+using TeleWave.Domain.Images;
+using Xunit;
+
+namespace TeleWave.Domain.Tests.Images;
+
+public class ImageTests
+{
+    [Theory]
+    [InlineData("jpg", ".jpg")]
+    [InlineData(".PNG", ".png")]
+    [InlineData("  .WebP ", ".webp")]
+    public void Create_NormalizesExtension(string input, string expected)
+    {
+        var img = Image.Create(ImageCategory.ShowPoster, input, "poster.jpg");
+
+        Assert.Equal(expected, img.FileExtension);
+        Assert.Equal(ImageCategory.ShowPoster, img.Category);
+        Assert.Equal("poster.jpg", img.OriginalFileName);
+        Assert.NotEqual(Guid.Empty, img.Id);
+    }
+
+    [Fact]
+    public void Create_BlankFileName_BecomesNull()
+    {
+        var img = Image.Create(ImageCategory.Library, ".jpg", "   ");
+        Assert.Null(img.OriginalFileName);
+    }
+}