[Aminark]

Description

useSet(new Set([NaN, 1])) reports that NaN is present, but both remove(NaN) and toggle(NaN) leave it in the set. Removal currently filters with strict inequality, for which NaN !== NaN.

Clone the previous set and use native Set.delete so removal follows the same equality semantics as membership. Toggling uses the same approach. Previous state snapshots, the caller's initial set, reset behavior, and stable action references are preserved.

Three regression cases cover NaN removal, toggling on/off, and immutable state/reset. All three fail against the original implementation.

Related: #2669 and #2687 propose broader ref-based rewrites. This PR keeps the existing immutable state implementation and addresses the NaN correctness issue only.

Type of change

• Bug fix (non-breaking)

Validation

• yarn test: 76 suites, 495 tests passed.
• yarn lint: passed with 0 errors and 97 warnings.
• yarn lint:types: passed.
• yarn build: CommonJS and ES module builds passed.
• Focused useSet/useMap/useList run: 56 tests passed; useSet statement, branch, function and line coverage are all 100%.
• git diff --check: passed.

Checklist

• Read the contributing guide.
• Reviewed the code and regression tests.
• Covered the behavior change with failing-before/passing-after tests.
• Test suite, lint, types and builds pass.
• Documentation and Storybook impact considered: no API changes or new usage to document.

AI assistance: OpenAI Codex prepared the implementation and tests, ran the checks, and drafted this PR.

Replaces #2729 after renaming the source branch; the commits are unchanged.