Add useScreenDimensions hook

[ahmedawaad1804]

React Native provides useWindowDimensions for subscribing to application window metrics, but components that need screen metrics must read Dimensions.get('screen') and manage their own subscription and cleanup.

This PR adds useScreenDimensions, the screen equivalent of useWindowDimensions. It returns width, height, scale, and fontScale, and updates subscribed components when any of these values change.

The hook uses useSyncExternalStore with a stable subscription and a cached snapshot. This handles updates between rendering and subscription, preserves snapshot identity when screen metrics are unchanged, and avoids unnecessary renders for window-only changes.

A motivating use case is screen-based drawer sizing on iPhone Duo when the application window and screen have different dimensions.

Includes public JavaScript and Flow exports, TypeScript declarations, the generated public API snapshot, and runtime and type tests.

Changelog:
[GENERAL] [ADDED] - Add useScreenDimensions to subscribe to screen width, height, scale, and font scale in React components.

Test Plan:
The following checks passed:

yarn test packages/react-native/Libraries/Utilities/tests/useScreenDimensions-test.js --runInBand
yarn build-types — regenerated TypeScript declarations and the public API snapshot.
yarn test-generated-typescript
yarn test-typescript-legacy
yarn flow-check — no errors.
ESLint and Prettier checks on all changed source files.
git diff --check
Tests cover initial screen metrics, changes to each metric, unchanged screen metrics during window updates, updates between rendering and subscription, subscription cleanup, subscription stability across updates, and current metrics after remounting.

Manual verification:

Render a component displaying both useScreenDimensions() and useWindowDimensions(). Rotate the device and, where supported, fold or unfold it. Confirm the screen hook follows the values reported by Dimensions.get('screen').
Verify drawer sizing on iPhone Duo and attach a recording showing the relevant window and screen dimensions.

[github-actions]

Warning

JavaScript API change detected

This PR commits an update to ReactNativeApi.d.ts, indicating a change to React Native's public JavaScript API.

• Please include a clear changelog message.
• This change will be subject to additional review.

This change was flagged as: POTENTIALLY_NON_BREAKING

[Abbondanzo]

@ahmedawaad1804 could you refrain from closing and reopening new copies of this PR? This is fine as is

[ahmedawaad1804]

@ahmedawaad1804 could you refrain from closing and reopening new copies of this PR? This is fine as is
@Abbondanzo
Sorry about that! I thought the older PRs might not get noticed or reviewed. I’ll keep all updates in this PR from now on.