Create a WAL-based key-value store that persists data to disk with crash recovery. The store must maintain a…

Create a WAL-based key-value store that persists data to disk with crash recovery. The store must maintain a…: a task in termgrade-bandcentral-gemma4-31b-bash: TermGrade Band-Central: the 151-task selection and its splits (Harbor dataset). Data directory: /data/kvstore/ WAL file…

The task

**Data directory:** `/data/kvstore/` **WAL file:** `/data/kvstore/wal.log` **Data file (after compaction):** `/data/kvstore/data.json`

Part of ai-and/termgrade-bandcentral-gemma4-31b-bash.