/**
 * [WHO]: planExtension - registers /plan command, EnterPlanMode/ExitPlanMode tools, plan mode state management, permission gating, and workflow prompt injection
 * [FROM]: Depends on core/extensions-host/types, ./types, ./plan-file-manager, ./plan-permissions, ./plan-workflow-prompt, ./enter-plan-mode-tool, ./exit-plan-mode-tool, ./plan-agents
 * [TO]: Auto-loaded by builtin-extensions.ts as a default extension
 * [HERE]: extensions/builtin/plan/index.ts - main plan mode extension entry point
 */
import type { ExtensionAPI } from "../../../core/extensions-host/types.js";
export default function planExtension(api: ExtensionAPI): Promise<void>;