/**
 * Task persistence: meta.json (single record) + events.jsonl (append-only log).
 *
 * Concurrency contract: applyEvent does a read-modify-write on meta.json. It
 * is safe to call from a single writer per task — by convention, that writer
 * is the _task-runner subprocess. CLI commands that need to influence a
 * running task (e.g. `franklin task cancel`) MUST signal the runner pid
 * (SIGTERM) rather than calling applyEvent directly, otherwise the two
 * writers race and one update is silently lost. Lost-task reconciliation
 * is an exception — it runs only when the runner is provably dead, so
 * there is no second writer to race with.
 *
 * Atomicity: writeTaskMeta uses tmp + rename; readers see either old or new
 * meta, never partial. appendTaskEvent relies on POSIX O_APPEND + PIPE_BUF
 * atomicity (~4096 bytes); summaries should stay short. readTaskEvents is
 * tolerant of a torn last line.
 */
import type { TaskRecord, TaskEventRecord } from './types.js';
export declare function writeTaskMeta(record: TaskRecord): void;
export declare function readTaskMeta(runId: string): TaskRecord | null;
export declare function appendTaskEvent(runId: string, event: TaskEventRecord): void;
export declare function readTaskEvents(runId: string): TaskEventRecord[];
export declare function applyEvent(runId: string, event: TaskEventRecord): TaskRecord;
export declare function listTasks(): TaskRecord[];