Use explicit IAsyncLifetime/IAsyncDisposable

Convert public async Task InitializeAsync/DisposeAsync methods to explicit interface implementations returning ValueTask (IAsyncLifetime.InitializeAsync and IAsyncDisposable.DisposeAsync). This hides the lifecycle methods from the public surface of the test class and aligns the test teardown/initialization with async disposal/lifecycle patterns.

Author: Taiizor

tests/Zetian.Tests/SmtpServerRaceConditionTests.cs

@@ -22,13 +22,13 @@ public SmtpServerRaceConditionTests()
             _testPort = TestHelper.GetAvailablePort();
         }
 
-        public async Task InitializeAsync()
+        async ValueTask IAsyncLifetime.InitializeAsync()
         {
             // Each test will create its own server to avoid interference
             await Task.CompletedTask;
         }
 
-        public async Task DisposeAsync()
+        async ValueTask IAsyncDisposable.DisposeAsync()
         {
             if (_server != null)
             {