refactor(useRefEffect): Improve useRefEffect hook by adding generic types in docs and strict null check in implementation

[wo-o29]

Overview

This PR introduces two distinct improvements to the useRefEffect hook:

1. Documentation and interface now include a generic type parameter, enhancing type safety and flexibility when using the hook with different HTMLElement types. This change improves developer experience by providing accurate typing information in the docs and type signatures.

2. The implementation has been updated to perform a strict null check (element === null) rather than a loose check. This strengthens type narrowing in TypeScript, ensuring that the callback is only called when a valid element is set, and avoids potential bugs related to falsy values.

Together, these changes make the hook safer to use and better documented without changing its external behavior.

Checklist

• Did you write the test code?
• Have you run yarn run fix to format and lint the code and docs?
• Have you run yarn run test:coverage to make sure there is no uncovered line?
• Did you write the JSDoc?

[Copilot]

Pull Request Overview

This PR enhances the useRefEffect hook by adding generic type parameters to improve type safety and strengthening the null check implementation. The changes improve developer experience through better TypeScript typing while maintaining the same external behavior.

• Added generic type parameter <E extends HTMLElement> to the hook interface for better type safety
• Updated null check from loose equality (== null) to strict equality (=== null) for more precise type narrowing
• Updated documentation to reflect the new generic type interface

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
src/hooks/useRefEffect/useRefEffect.ts	Strengthened null check from loose to strict equality
src/hooks/useRefEffect/useRefEffect.md	Updated interface documentation to include generic type parameter
src/hooks/useRefEffect/ko/useRefEffect.md	Updated Korean documentation to match generic type interface

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[Copilot]

The strict null check element === null will not catch undefined values, which could cause the callback to be executed with undefined. The original loose equality check == null was correct as it handles both null and undefined cases. This change could introduce bugs when the element is undefined.

Suggested change

	if (element === null) {
	if (element == null) {

[wo-o29]

Since instance is of type T | null as in React CallbackRef Type, I don't think we need to check for undefined. What do you think?

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (5bdb4ff) to head (a8ecfc4).
⚠️ Report is 6 commits behind head on main.

Additional details and impacted files

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  Files           37        37           
  Lines         1093      1093           
  Branches       324       324           
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  Hits          1093      1093           

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