Interface Checkpointer

A save/load hook a durable-execution backend can implement against.

This is deliberately a small seam, not a workflow engine: no retry or journaling semantics, no exactly-once guarantees. A production Checkpointer (backed by Temporal, Inngest, a database, etc.) is expected to be supplied by the application, not intellibrix itself.

interface Checkpointer {
load(runId: string): Promise<CheckpointState | undefined>;
save(runId: string, state: CheckpointState): Promise<void>;
}