feat: ios 26 style support

### Prerequisites

- [x] I have read the [Contributing Guidelines](https://github.com/ionic-team/ionic-framework/blob/main/docs/CONTRIBUTING.md#creating-an-issue).
- [x] I agree to follow the [Code of Conduct](https://ionicframework.com/code-of-conduct).
- [x] I have searched for [existing issues](https://github.com/ionic-team/ionic-framework/issues) that already include this feature request, without success.

### Describe the Feature Request

Add support for iOS 26 design language across Ionic components. This includes updated styles, transitions, system interactions, new native UI behaviors, and any system-level visual changes introduced in iOS 26. The goal is to ensure Ionic apps continue to feel native and aligned with Apple’s latest design standards.

### Describe the Use Case

Apps built with Ionic targeting iOS should reflect the current system design to maintain a modern, platform-consistent user experience. With iOS 26 introducing changes to gestures, components, or animations, this feature would help developers adopt the latest platform expectations without custom hacks or overrides.

### Describe Preferred Solution

There are two possible approaches:
Introduce a new mode, mode="ios26", that specifically implements the styles and behaviors of iOS 26. This would allow developers to opt into the new design without affecting existing apps using the current ios mode.

Or alternatively:
Update the existing mode="ios" to reflect the new design changes in iOS 26, while ensuring backwards compatibility. This could be achieved through feature flags, version checks, or fallback mechanisms to maintain consistent behavior for apps targeting older iOS styles.

In both cases, the update should include changes to animations, component styles (e.g. modals, buttons, segment controls), and any new system behaviors introduced in iOS 26.

### Describe Alternatives

- Manually override styles and animations via custom CSS and JS to mimic iOS 26 behavior (not ideal).
- Wait for community plugins or forks to introduce these updates (fragmented and inconsistent).

### Related Code

_No response_

### Additional Information

_No response_

The issue names no files, tests, or entry points. Begin by mapping the existing iOS mode and Ionic components, then define the required iOS 26 styles, transitions, and system interactions; done means the selected mode or existing iOS mode consistently reflects the requested design while preserving older behavior.

Scritto dal modello di indicizzazione a partire dal testo della issue.