1.1 MacAddress value type

Permissive parser (colon, hyphen, unseparated; case-insensitive; surrounding
whitespace) with canonical lowercase no-separator ToString. Implements
IParsable/ISpanParsable for ASP.NET route binding and ships a System.Text.Json
converter that normalizes on read.

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

tests/FrameProcessor.Tests/UnitTest1.cs

@@ -1,10 +1 @@
-namespace FrameProcessor.Tests;
-
-public class UnitTest1
-{
-    [Fact]
-    public void Test1()
-    {
-
-    }
-}
+namespace FrameProcessor.Tests;