fix(types): expose Modal native ref prop

[ya-nsh]

Summary

• add modalRef to the hand-written Modal TypeScript declarations
• export PublicModalInstance from Modal.d.ts to match the generated API snapshot
• add a typetest for passing a HostInstance ref through modalRef

Modal already accepts modalRef at runtime and the generated API snapshot already includes it. The hand-written declarations were the odd one out, so TypeScript users could not pass the supported ref prop without a local cast.

Changelog:

[General] [Fixed] - Expose Modal native ref prop in TypeScript declarations

Test Plan

• npx prettier --check packages/react-native/Libraries/Modal/Modal.d.ts packages/react-native/types/__typetests__/index.tsx
• npm run test-typescript -- --pretty false
• npm run build-types
• npm run test-generated-typescript -- --pretty false

[cipolleschi]

@ya-nsh thanks for the contribution, but why is it needed? This increases our API surface, so unless there is a concrete reason why we need it, we would rather not have a new piece of API that we need to maintain.

Can you update the summary with the reason why we need the ref prop?

[ya-nsh]

Thanks, that makes sense. I updated the summary with the reason now.

The short version is that Modal already accepts modalRef at runtime, and the generated API snapshot already exposes it. This change just brings the hand-written TypeScript declaration in line with that, so TS users do not need a local cast to use the existing prop.

[ya-nsh]

Friendly review ping: this PR is ready for maintainer review when you get a chance. Known status: 11 check(s) currently failing; I can follow up if review points to needed changes.

Happy to adjust quickly if you want a different shape or narrower scope.

[meta-codesync]

@cipolleschi has imported this pull request. If you are a Meta employee, you can view this in D105968862.

[huntie]

Can we align with the (few) other uses in our types currently, to use React.RefObject (example).

Suggested change

	modalRef?: React.Ref<PublicModalInstance> | undefined;
	modalRef?: React.RefObject<Modal | null> | undefined;

This then means the usage (in __typetests__/) can be simplified as so.

- // Non-obvious use of HostInstance in lieu of PublicModalInstance not being exported
- const modalRef = React.useRef<HostInstance>(null);
+ // Resolvable via component type under TypeScript
+ const modalRef = React.useRef<Modal>(null);

Disclaimer: I'm actually working on a bigger item around ref types for the new Strict TypeScript API in #56673. I'm not 100% certain this type change will endure in the final state, but for now it's aligned with what we have / how other usages are possible today.