Add performance benchmark tests for critical rendering paths including Measure/Arrange operations on flat layouts (100 children), deep nesting (20 levels), and Grid layouts (10x10). Include HitTest performance validation. Tests use Stopwatch with generous upper bounds to catch regressions while avoiding flaky failures on slow CI machines. Benchmarks verify operations complete within acceptable time budgets (5-10ms thresholds).
Add comprehensive test coverage for 20+ Skia controls including ActivityIndicator, Border, CheckBox, CollectionView, DatePicker, Editor, Grid, Image, ImageButton, Label, NavigationPage, Page, Picker, ProgressBar, RadioButton, SearchBar, Stepper, Switch, and TimePicker. Include tests for TextRenderingHelper utility methods covering color conversion, font style mapping, and font family resolution.
