v5.6.0 — WAL Crash Recovery

All 3,136 tests pass. Zero TypeScript errors.

All 3,136 tests pass. Zero TypeScript errors.

Features

LockedBlackboard Write-Ahead Log (WAL) crash recovery (lib/locked-blackboard.ts)

Every write(), commit(), and delete() now follows a strict append-before-write + checkpoint-after-write pattern:

1. Before the file write — an append record is written to .wal.jsonl
2. The actual state file is updated
3. After the write succeeds — a checkpoint record is appended to .wal.jsonl

On construction, replayWAL() is called automatically after loadFromDisk(). It scans .wal.jsonl for any append records that have no matching checkpoint (= the process crashed between steps 1 and 3) and replays them into the in-memory store. The WAL is then compacted.

// WAL is automatic — nothing to configure
const board = new LockedBlackboard('.', { env: 'prod' });
// Any uncommitted ops from a previous crash are replayed here

// Manual truncation after a full snapshot:
await board.compactWAL();

WAL file locations

Resilience properties

• Partial writes at crash time produce malformed tail lines — silently skipped
• WAL replay is idempotent: replaying an already-committed op overwrites with the same value
• compactWAL() is safe to call at any time; a new WAL starts clean on the next write

7 new tests added to test-phase11.ts.