Add debounce to slider onChange; truncate slider labels to specified precision

[tom-vx51]

Rationale

The slider component currently has two problems:

• onChange events are fired for every change, which is very noisy when e.g. dragging a slider knob
• Labels are not truncated to the specified step value, resulting in poor readability with high-precision values

Changes

• Debounce onChange events
• Truncate slider labels to specified step

Testing

storybook

Screen.Recording.2026-02-06.at.5.35.45.PM.mov

[marcus-kestler]

You don't need to debounce the slider. It should be on mouseup which is already handled in SliderBar. Just emit a final event like "changeComplete" and use that to trigger the save.

[tom-vx51]

You don't need to debounce the slider. It should be on mouseup which is already handled in SliderBar. Just emit a final event like "changeComplete" and use that to trigger the save.

this has nothing to do with saves, it was always intended to be debounced

[erik-nieh]

Step value/truncating looks good

@marcus-kestler I think debouncing this change is abstractly useful for this component - it will probably improve the HA experience but is necessary for future features/work as well.

[erik-nieh]

This feature is great.

We had a very poor custom implementation related to stepper motor testing with pytest that always caused trouble in a previous job.

[erik-nieh]

Can we make this a prop? There might be some use cases in the future where a "live" slider is useful.