Reconciles the vector-index rename to the ruled three-layer naming: the
provider contract's identity field is now a REQUIRED readonly name (was
optional providerId), self-reported and truthful, rendered as
[vector-index:<name>] where the index identifies itself and stamped into
the op-name strings journals already parse (AddToVectorIndex(<name>)).
The built-in JS engine names itself hnsw-js. A runtime provider instance
compiled against the previous optional contract is tolerated - never
crashed on, never silently mislabeled: it stamps unknown-provider and
emits one loud warning naming the missing field. Graph index operations
keep their static names (they never interpolate provider identity), and
no public API exports a provider-routed hnsw-carrying name, so no
deprecation shim is required.