fix(app): set aria-checked directly on Switch so toBeChecked() assertions work

RNW's createDOMProps maps direct aria-* props to the DOM but does not
read from accessibilityState.checked. The Switch was relying on the
latter, so no aria-checked attribute was ever rendered — making the
component opaque to screen readers and breaking Playwright's
toBeChecked() assertions in E2E tests. Passing aria-checked={value}
alongside the existing accessibilityState fixes both.

packages/app/src/components/ui/switch.tsx

@@ -99,6 +99,7 @@ export function Switch({
       hitSlop={8}
       accessibilityRole="switch"
       accessibilityState={accessibilityState}
+      aria-checked={value}
       accessibilityLabel={accessibilityLabel}
       testID={testID}
       style={pressableStyle}