[Epic] P3 — Backup, Restore & PITR (v0.7)

[habibtalib]

Epic — v0.7 production-hardening, phase P3: Backup, Restore & PITR

Goal: an operator can take scheduled backups and restore to an exact point in time, verified.

High

• PITR is inert scaffolding — execute_restore, create_base_snapshot, WalArchiver, SnapshotCatalog have zero production callers; no base-snapshot task is scheduled; resolve_pitr always returns None. Reads as shipped but cannot be invoked. Replay also ignores PitrTarget.replay_lsn (no upper bound). storage/snapshot_executor.rs, storage/snapshot.rs:147-174, wal/archiver.rs:233-250 (filename parser also broken — expects wal-{first}-{last}.seg, real is wal-{lsn}.seg).

Medium

• WAL-archive upload failures only warn!; truncation proceeds → hole in the archived stream → PITR continuity broken. checkpoint_manager.rs:214-217,336-388.
• Hand-rolled UTC/leap-year math for PITR targets ("production should use chrono") → off-by-one → wrong LSN. snapshot_restore.rs:101-172.
• Restore staleness gate bypassed on lock poisoning → stale envelope overwrites newer writes. backup/restore/mod.rs:80-97.
• No restore verification (post-restore row-count/checksum reconciliation).
• Backup is full-snapshot only — no incremental/differential, no scheduling/retention.

Success: scheduled base snapshots + WAL archiver wired; restore replays to a target LSN/timestamp; end-to-end "base + WAL → restore to T, assert state == state@T" test passes.

Tracked in .planning/v1-production-readiness/AUDIT.md.