Adds : an append-only JSONL ledger that
survives process restart and reconstructs queue/worker state.
- Records runs, task inbox entries, leases, lifecycle events, heartbeats,
receipts, and alert decisions.
- Replays the ledger to rebuild on startup.
- Atomic temp-file writes guard against partial writes; malformed lines
are skipped during replay.
- Provides , , , , and a
compaction helper.
- Six tests cover create/rebuild, enqueue/claim, restart survival,
partial-line tolerance, event/heartbeat reconstruction, and receipts.
Closes#3156.
Hunter B