/**
 * Tracks headless child processes (spawned `pi --mode rpc` sessions) so a
 * killed host never leaves orphans working. Children spawn in their own
 * process group; the registry file lets a later host reap leftovers by
 * killing the whole group. The file lives next to the project store and is
 * only ever touched by one host at a time (the advisory lock ensures it).
 */
export declare class HostProcessRegistry {
    private readonly filePath;
    private readonly pids;
    constructor(storeDir: string);
    register(pid: number): void;
    unregister(pid: number): void;
    get size(): number;
    /** Kill every registered child's process group, escalating to SIGKILL. */
    killAll(): void;
    /**
     * Reap children recorded by a previous host that died without cleanup.
     * Called once at host start, before the lock is taken.
     */
    reapOrphans(): number[];
    private readFile;
    private persist;
}