mlx-bun library API
    Preparing search index...
    interface ChunkRow {
        conv: string;
        end: number;
        id: string;
        label: string | null;
        start: number;
    }
    Index
    conv: string
    end: number
    id: string

    Deterministic id ${conv}:${start}-${end} — idempotent re-chunking.

    label: string | null
    start: number