// Polyfill for Object.groupBy (requires Node.js 21+, we're on 20)
// This must be imported before any code that uses Object.groupBy
if (typeof Object.groupBy === 'undefined') {
  Object.groupBy = (items, keyFn) => {
    const result = {}
    let index = 0
    for (const item of items) {
      const key = keyFn(item, index++)
      ;(result[key] ??= []).push(item)
    }
    return result
  }
}