will.anderson
8affb1d6e0
Write-back no-steal buffer pool makes the fsync'd WAL load-bearing (M1 was write-through). Logical WAL with record-granularity page-LSN redo idempotency. Checkpoint = flush dirty pages, fsync store, advance last_checkpoint_lsn, reclaim WAL prefix. One-time snapshot.json import only when store absent; JSON never read as the ongoing store thereafter. Gates: 33/33 M1 (no regression) + 36/36 M2 — replay parity, torn-tail fuzz (every byte offset), checkpoint-crash at all 5 phases, torn-page+WAL redo, legacy-import parity, hebb-survives-crash.