/refactor

Refactor the selected code. Goals in priority order:

1. Correctness — preserve exact behavior (don't change what it does)
2. Clarity — improve naming, reduce nesting, split complex functions
3. Idioms — use language/framework conventions (e.g. array methods, optional chaining)
4. Simplicity — remove dead code, unnecessary abstractions, and over-engineering

Show the refactored version with a brief explanation of what changed and why. If a change is non-trivial or has a tradeoff, call it out.