Function initReminder

src/lib/reminders.ts:21–24

(solvedDate: string)

// Create the first reminder from a solved date
export function initReminder(solvedDate: string): Reminder {
  const dateOnly = solvedDate.slice(0, 10);
  return { nextReview: addDays(dateOnly, SCHEDULE[0]), interval: SCHEDULE[0] };
}

// Advance to the next interval. Returns null if past the last interval (schedule complete).
export function advanceReminder(current: Reminder): Reminder | null {