<?php

declare(strict_types=1);

namespace App\Domain\Time;

use DateTimeImmutable;

/**
 * Injected wall clock. Tests substitute a fixed-time implementation so
 * `received_at`, decay age, and rate-limit refill calculations are
 * reproducible. Production wires `SystemClock`.
 */
interface Clock
{
    public function now(): DateTimeImmutable;
}
