OptionalcollapsedFolded away to just its header bar. 'auto' follows the room available, until
the first explicit collapse or expand hands control to the user for good.
OptionalheightExpanded height: a pixel count, or a fraction of the canvas between 0 and 1.
OptionalopenWhether the region is present, and expanded when it is. Three states, because the collapsed bar is the control that opens it:
true — present and expanded.false — not present at all. Shift+T still brings it in.
UI.dock— the bottom dock's own settings: the region, not its occupants.Everything about what is in the dock is declared elsewhere — the table under
UI.table, anything else throughaddDockTab(). What is left here is the region the occupants share, which is why there is exactly one of each setting however many tabs are registered.Example