Function toDateString

src/utils/statsCache.ts:403–410

(date: Date)

 * Extract the date portion (YYYY-MM-DD) from a Date object.
 */
export function toDateString(date: Date): string {
  const parts = date.toISOString().split('T')
  const dateStr = parts[0]
  if (!dateStr) {
    throw new Error('Invalid ISO date string')
  }
  return dateStr
}

/**
 * Get today's date in YYYY-MM-DD format.