durability

Always DurabilityState.AsPromised, because this backend promises nothing.

Not a stub, and not a gap waiting for an implementation. Bolt.durability is relative: it reports whether a backend is meeting the level it offered, and this one offers no durability at all — there is no flush to fail, no volume to refuse, and on wasmJs not even a page reload to survive. Nothing it said can be broken, so nothing here can fall short of it.

The absolute reading — "these bytes are not on a platter, so report degraded" — is true and useless: it would latch on every target from construction, telling a consumer only what this class's KDoc already says out loud, and drowning the one signal that means something.