OptionalliveEmit colour and slider edits on input as well as change, for a dialog
that previews live. Off, a colour is one edit when the picker closes and a
slider one edit on release, which is what a per-edit undo history wants.
OptionalopenShared overlay owner for nested colour pickers.
Show el over the widget: positioned from opts.anchor (or centred as a
dialog), focus-trapped, closed by Escape and by a press outside. Returns
the closer.
Optionalopts: OverlayOptionsOptionalpreserveKeep an invalid numeric draft visible for validation when a form is saved.
OptionaltranslateTranslates widget-owned text. Omit to preserve English rendering.
OptionalcustomRenders the control column of a custom row. Null skips the row.
OptionalunavailableWhy a control, or one option of a select, cannot act right now, or null
when it can. Drawn disabled with the reason as its title, never hidden: a
greyed row is information, an absent one is a mystery. Asked again after
every edit and every sync, beside the control's activeWhen, and its
reason wins where both apply because the host knows the context.
Optionaloption: string
Prefix for element ids, so two forms in one document never share one.