* fix(vector_store): stop dropping metadata for add_vectors-only backends
VectorStore.store_vectors() previously discarded the metadata argument
whenever the backend only exposed add_vectors() (e.g. FAISSStore), even
though add_vectors() supports it. Now metadata is forwarded, and is only
passed when the backend's add_vectors() signature actually accepts it
(checked via inspect.signature), avoiding a TypeError for stricter
backend signatures.
Fixes#832
* fix(vector_store): guard signature introspection in store_vectors
inspect.signature() can raise ValueError/TypeError for some callables
(e.g. certain C-implemented or dynamically built methods). Wrap the
add_vectors() signature probe in try/except, consistent with the same
pattern already used in ProvenanceManager.trace_lineage(), defaulting
to attempting to pass metadata when introspection fails.
* docs(changelog): document VectorStore metadata-drop fix (#832, #835)
* test(vector_store): add regression coverage for metadata forwarding
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Co-authored-by: Sameer6305 <sskadam6305@gmail.com>
