feat(useAsyncEffect): support synchronous cleanup functions

[pentaoa]

🤔 This is a ...

• New feature
• Bug fix
• Site / documentation update
• Demo update
• TypeScript definition update
• Bundle size optimization
• Performance optimization
• Enhancement feature
• Internationalization
• Refactoring
• Code style optimization
• Test Case
• Branch merge
• Other (about what?)

🔗 Related issue link

Closes #2954

💡 Background and solution

useAsyncEffect currently accepts promises and async generators, but callers cannot return a normal React cleanup function. The hook now detects a synchronous function result and returns it directly from useEffect, preserving React's standard cleanup timing on dependency changes and unmount.

The asynchronous promise/generator cancellation path is unchanged.

📝 Changelog

Language	Changelog
🇺🇸 English	useAsyncEffect now supports returning a synchronous cleanup function.
🇨🇳 Chinese	useAsyncEffect 现在支持返回同步清理函数。

☑️ Self Check before Merge

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• TypeScript definition is updated/provided or not needed
• Changelog is provided or not needed

Validation

• vitest run packages/hooks/src/useAsyncEffect/__tests__/index.spec.ts (4 tests)
• tsc --noEmit -p packages/hooks/tsconfig.json
• Biome formatting check for the four changed files
• git diff --check

AI assistance

Codex assisted with implementation, type-checking, and tests. I reviewed the complete diff and take responsibility for the change.

[pkg-pr-new]

npm i https://pkg.pr.new/ahooks@2958

npm i https://pkg.pr.new/@ahooks.js/use-url-state@2958

commit: 0037f43

[crazylxr]

LGTM