OptionalclassOptionaldefaultTab shown first when the modal opens; defaults to "properties".
OptionalmodeProperty tab mode; defaults to "edit" since the modal is a workspace.
Open for this node id; closed (renders nothing) when null.
Close handler (e.g. clears the selection that opened the modal).
OptionalonProperty change passthrough (edit mode).
OptionalspecProperty spec passthrough for the Properties tab.
UGM instance the panels read from.
CSS class for the backdrop.