/**
 * [WHO]: grubExtension default export - registers /grub command, completions, dual-phase prompts, resume support, feature-list validation, and grub renderer
 * [FROM]: Depends on @catui/agent-core, @catui/tui, core/extensions-host/types, core/runtime/event-bus, ./grub-controller, ./grub-format, ./grub-parser, ./grub-types, ./grub-harness, ./grub-prompts, ./grub-persistence, ./grub-turn
 * [TO]: Auto-loaded by builtin-extensions.ts as a default extension
 * [HERE]: extensions/builtin/grub/index.ts - autonomous iterative task runner with Anthropic-style long-running harness (feature-list.json + durable state + phase-specialized prompts)
 */
import type { ExtensionAPI } from "../../../core/extensions-host/types.js";
export default function grubExtension(api: ExtensionAPI): Promise<void>;