fix: respect threshold before trigger once cleanup

[thebuilder]

Summary

• use the threshold-aware inView result before cleaning up a triggerOnce observer
• keep observing when the browser reports an intersection below the configured threshold
• add regression coverage for a below-threshold entry followed by an at-threshold entry

Fixes #756.

Verification

• corepack pnpm exec vitest run src/__tests__/useInView.test.tsx
• corepack pnpm exec vitest run
• corepack pnpm exec tsc --noEmit
• corepack pnpm exec biome check src/useInView.tsx src/__tests__/useInView.test.tsx
• corepack pnpm build

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[vercel]

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Project	Deployment	Actions	Updated (UTC)
react-intersection-observer	Ready	Preview, Comment	Jul 14, 2026 11:05am

[pkg-pr-new]

npm i https://pkg.pr.new/react-intersection-observer@762

commit: 560e3fa