One backend-agnostic interface through which every read, integrity check, and preservation transition is funneled.
The Storage Abstraction Layer is the only component that touches storage. Every read, integrity check, mutation, and preservation transition in the estate is funneled through one interface, so enforcement behaves uniformly regardless of the medium underneath.
That single point of contact is what makes governance portable. The same policy produces the same enforcement whether the underlying storage is a local filesystem, an object store with retention capability, or an enterprise storage platform.
The interface exposes a deliberately small set of primitives covering reading, integrity verification, writing, retention locking, isolation, migration, and status. Constraining the surface is what allows every storage action to be governed and recorded consistently.
Structural refusals are part of the contract: writes to a retention-locked asset and writes to sources the system does not own are refused by construction, and both the refusal and its reason are recorded.
Assets occupy explicit physical states (active, locked, quarantined, and cold) and transitions between them are the visible consequence of governance decisions rather than manual administration.
Every action taken through the layer, whether automatic or operator-initiated, is written to an action record and chained into the verification ledger, so the physical history of an asset is reconstructable.
All storage interaction passes through one governed interface.
Uniform behavior across local, object, and enterprise storage.
Disallowed writes refused by construction and recorded.
Active, locked, quarantined, and cold as governance outcomes.