Interface PanelLike

The minimal contract a registered panel/tool can satisfy.

Every member is optional because the registry covers both visual panels (which all implement the full set) and non-UI tools like TransformControls that have no visibility concept. The registry calls each member with optional chaining, so tools without UI just no-op the visibility branches.

interface PanelLike {
    visible?: boolean;
    hide(): void;
    show(): void;
    toggle(): void;
}