Module layout 

Pure tiered storage layout derivation.

This module maps a configured database path and layout preset to deterministic sidecar paths. Constructors and accessors perform no I/O; callers opt into directory creation through TieredLayoutPaths::ensure_dirs.

Structs

LayoutOverrides

Optional per-toggle override applied after preset expansion.

LayoutToggles

Fully expanded layout toggles after applying a preset and overrides.

TieredLayoutPaths

Deterministic paths derived from a data file and expanded layout.

Enums

StorageLayout

Storage layout preset for future tier-aware startup integration.