Popover

A panel anchored to what opened it: position, click outside, Escape and focus return, all in one place.

When to use it

A small panel should open over an element — list filters, a picker, a piece of detail that would be too heavy as a dialog.
You are building your own menu or picker and do not want to write positioning and dismissal again. IngotMenu stands on exactly this.
The panel must also open from inside a dialog — the MENU_LAYER layer keeps it above, not under.

The content needs focus on one thing and a confirmation — that is IngotModal. A popover deliberately does not trap focus, so Tab leaves it.
An edit made while working with the list behind it — that is IngotDrawer.
A short description of a control. That is IngotTooltip; a popover is for content you work with.

open: boolean — Controlled — the caller owns the state, as with every overlay in the kit.
anchorRef: RefObject<HTMLElement | null> — The element the panel hangs from. A click on it does not close the panel — it is a toggle.
onClose: () => void — Called by Escape and by a click outside. Escape also returns focus to the anchor.
placement: "bottom-start" | "bottom-end" | "top-start" | "top-end" — The preferred side. When there is no room below the anchor and there is above, it flips.
label: string — Translated name of the panel. Required: an unnamed panel is announced as just a group.
className: string — The panel's layout only — width, padding.
testId: string — An anchor for tests.