/**
 * Monotonic timing for spans (performance.now when available; else coarse wall fallback).
 */
export function bareOsMonotonicNowMs() {
  if (typeof globalThis.performance?.now === 'function') {
    return globalThis.performance.now()
  }
  return Date.now()
}

/**
 * @param {number} startMs
 */
export function bareOsMonotonicElapsedMs(startMs) {
  return Math.max(0, bareOsMonotonicNowMs() - startMs)
}