// ❌ LEAK: Missing cleanup
function Component() {
  useEffect(() => {
    window.addEventListener('scroll', handleScroll);
    // Missing: return () => window.removeEventListener('scroll', handleScroll);
  }, []);
}

// ✅ CORRECT
function Component() {
  useEffect(() => {
    window.addEventListener('scroll', handleScroll);
    return () => window.removeEventListener('scroll', handleScroll);
  }, []);
}

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