/**
 * Shared E2E helper to test the DarkModeController integration on a component.
 *
 * @param tag         The custom element tag to test (e.g. `p-button`)
 * @param innerSelector The selector pointing to the element holding `is--dark`,
 *                    relative to the host. Use `>>> .papier` for shadow components,
 *                    or `.papier` for light-DOM components.
 * @param attrs       Optional extra attributes appended to opening tag.
 */
export declare function runDarkModeControllerTests(tag: string, innerSelector: string, attrs?: string): void;