phase(N.5) Task 2 fixup: name TexImage3D depth + border arguments

Code quality review caught that the TexImage3D call dropped the
depth: and border: named arguments specified in the plan. The bare
positional `1, 0` is hard to disambiguate from the surrounding 10
parameters. Adds them back, no runtime change.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/AcDream.App/Rendering/TextureCache.cs

@@ -296,8 +296,8 @@ public sealed unsafe class TextureCache : Wb.ITextureCachePerInstance, IDisposab
                 InternalFormat.Rgba8,
                 (uint)decoded.Width,
                 (uint)decoded.Height,
-                1,
-                0,
+                depth: 1,
+                border: 0,
                 PixelFormat.Rgba,
                 PixelType.UnsignedByte,
                 p);