Relative time formatting inconsistent with Home Assistant

[awahlig]

Describe the bug
When displaying Last Changed of an entity, the relative time on the Bubble Card is sometimes displayed differently than how it's shown in HA. The value is sometimes off by 1 ("4 hours" on the card, "5 hours" in HA).

Specifically, I'm seeing this for a binary_sensor and a "State" Bubble Card. Tapping the card shows the "more info" view where HA's formatting can be seen.

Looking at the code, I think it's because Bubble Card uses Math.floor() whereas HA uses Math.round():
https://github.com/home-assistant/frontend/blob/56ab29da81402ba469f47b4f55bba7f28c5bdf52/src/common/util/select-unit.ts#L20

To Reproduce
Steps to reproduce the behavior:

1. Enable showing of Last Changed on a card.
2. Compare the time with what HA is showing.

Expected behavior
The formatting should ideally be consistent with HA.

Informations (please complete the following information):

• Bubble Card version: 2.4.0
• Home Assistant version: 2025.2.2