Implement a write-ahead log (WAL) key-value store with crash recovery. The store must persist data to disk…

Implement a write-ahead log (WAL) key-value store with crash recovery. The store must persist data to disk…: a task in TermGrade Environments: 1,004 executable Linux tasks (Harbor dataset). Files on disk: - data/wal.log — the write-ahead log. Append-only. Each operation is one line. -…

The task

**Files on disk:** - `data/wal.log` — the write-ahead log. Append-only. Each operation is one line. - `data/store.json` — the current state snapshot. Created/overwritten after every `put`, `delete`, and `recover`. Must be valid JSON representing a flat object of string→string.

Part of ai-and/termgrade-environments.