PR Checklist

• The PR title follows our guidelines: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/CONTRIBUTING.md#commit-messages.
• There is an issue for the bug/feature this PR is for. To avoid wasting your time, it's best to open a suggestion issue first and wait for approval before working on it.
• You have signed the CLA.
• All existing tests are passing: https://github.com/NativeScript/NativeScript/blob/master/tools/notes/DevelopmentWorkflow.md#running-unit-tests-application.
• Tests for the changes are included - https://github.com/NativeScript/NativeScript/blob/master/tools/notes/WritingUnitTests.md.

What is the current behavior?

Currently, only on iOS 26, the ActionBar with iosLargeTitle="true' would overlap titles when navigating back from pages.
Also, Switch was previously hardcoding dimensions which weren't needed and interfered with style changes in iOS 26.

What is the new behavior?

• ActionBar and Switch cases are now handled.
• Includes iOS 26 types updates.
• Additionally, because iOS 26 brings about some specific styling considerations, new root level CSS scoping is now possible, for example:

.ns-ios-26 .action-bar {
    /**
     * Note: nativescript-theme-core auto adds background-color to actionbar 
     * doing so will cause iOS 26+ to not render titles when large title is enabled 
     * We can now scope specific styling behavior for platform sdk versions
     */
    background-color: transparent;
}

You can also do this for .ns-android-36 or .ns-visionos-2, etc.