useHostedSlot

Resolve a chrome slot the way the surrounding chrome resolves it.

There are two component maps — TldrawUi carries its own, DefaultUi uses the editor's — and the panels below are rendered by both. Reading only one of them is how the hosted row first rendered nothing at all: the slot was set, in the other map. null stays null, so components={{ … : null }} still means "remove it" even though it is a panel that draws it.