Apply code style formatting and restore partial modifiers on Avalonia views

Linter/formatter pass across the full codebase. Restores required partial
keyword on AXAML code-behind classes that the formatter incorrectly removed.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/ZB.MOM.WW.LmxOpcUa.Client.UI.Tests/ReadWriteViewModelTests.cs

@@ -149,4 +149,4 @@ public class ReadWriteViewModelTests
         _vm.SelectedNodeId = null;
         _vm.IsNodeSelected.ShouldBeFalse();
     }
-}
+}