Agent Skills: ui-tests-migration

Create, migrate, and stabilize PowerToys UI tests with Microsoft.PowerToys.UITest.Next and winappcli, through local VM success, commit/push, and CI validation. Use for ports, new UITest projects, flaky CI tests, persistent Hyper-V validation, Settings IPC authentication/test signing, Explorer/Shell selection, preview handlers, thumbnail providers, hotkey activation, stateful process lifecycle, composed WinUI/WebView visual baselines, or foreground failures. Covers APIs, scaffolding, test design, diagnostics, and the required handoff to ui-tests-pipeline-ci. Keywords: UI test, UITests, UITestAutomation.Next, winappcli, WinAppDriver, Selenium, Settings IPC, not-microsoft-signed, Authenticode, local VM, Hyper-V, checkpoint, migrate, flaky, CI stability, Explorer, Shell extension, WebView2.