/**
 * Approval-panel collapse button.
 *
 * Pure DOM helpers, no framework imports — unit-testable in jsdom. The
 * harness ApprovalPanel body (`[data-approval-scroll]`: the red/green diff
 * headline plus the optional command line) can be hundreds of lines tall and
 * hides the agent's output behind the composer. This module installs a
 * disclosure button at the strip's right end (the card's top-right corner)
 * that toggles the body visibility via a card class — CSS-only show/hide,
 * the diff DOM stays intact, so expanding restores the exact same view with
 * no re-render.
 *
 * @module dsh-edit-approval/client/collapse
 */
/** Card class toggled by the collapse button (the body-hiding rule lives in {@link COLLAPSE_STYLE}). */
export declare const COLLAPSED_CLASS = "dsh-ea-collapsed";
/** Class of the injected disclosure button. */
export declare const COLLAPSE_BUTTON_CLASS = "dsh-ea-collapse-btn";
/**
 * Collapse-button styling plus the body-hiding rule. Scoped by the panel
 * root anchor and the card class, so it never leaks outside an approval
 * panel. Merged into the plugin's injected `<style>` by `index.ts`.
 */
export declare const COLLAPSE_STYLE: string;
/** Action labels for the disclosure button (resolved through the locale service). */
export interface CollapseLabels {
    /** Label shown while expanded ("collapse approval details"). */
    readonly collapse: string;
    /** Label shown while collapsed ("expand approval details"). */
    readonly expand: string;
}
/**
 * Install the collapse button on one approval panel. No-op unless the
 * headline is multi-line (a real diff — single-line escalation approvals
 * keep the native compact panel) and the button is not already installed.
 * The button lives at the strip's right end; clicking toggles the
 * `dsh-ea-collapsed` class on the panel root, flips `aria-expanded` and the
 * action label, and leaves the diff DOM untouched.
 * @param panel - the `[data-approval-key]` panel root.
 * @param labels - localized button labels.
 */
export declare function installCollapseButton(panel: Element, labels: CollapseLabels): void;