Module error 

Storage tier + WAL replay error types (Phase 14.6 — DS-14-storage Q3/Q9).

• StorageError — tier-level preconditions (backend lacks capability, codec mismatch, backend I/O failure). Surfaced by BaseStorageTier operations (M4.B+).
• RestoreError — replay-time failures from Graph::restore_snapshot({ mode: "diff" }) (M4.E). Distinct from StorageError so callers can disambiguate “tier broken” from “replay couldn’t complete”.
• RestoreResult — telemetry returned on successful replay (inspection-as-test-harness shape per CLAUDE.md dry-run rule).

Both error enums mirror the TS impl at packages/pure-ts/src/extra/storage/wal.ts:194-251; variant names align with the TS string discriminants for parity-test diffability.

Structs

PhaseStat

Per-lifecycle phase telemetry within a RestoreResult.

RestoreResult

Telemetry returned by a successful restore_snapshot({ mode: "diff" }) call. Every field is observable so tests + dry-run audit paths can pin replay invariants (CLAUDE.md dry-run equivalence rule).

Enums

RestoreError

Replay-time failures from Graph::restore_snapshot({ mode: "diff" }).

StorageError

Tier-level preconditions surfaced by BaseStorageTier operations.