* feat(vector_stores): add Amazon OpenSearch as a vector store provider
* feat(ui): add Amazon OpenSearch to the vector store provider dropdown
* feat(vector_stores): add OpenSearch k-NN search as a vector store provider
* test(vector_stores): hold the OpenSearch provider tests alone for the first review
The provider source comes back in the next commits on this PR
* ci(tests): run the OpenSearch vector store unit tests
* fix(vector_stores): sign on.aws and FIPS OpenSearch hosts and reject missing AWS credentials before embedding
* fix(vector_stores): regenerate provider endpoint support for opensearch
* fix(vector_stores): keep opensearch retrieve, update, and delete off the index and refuse half-set AWS keys and per-account endpoints
* fix(vector_stores): return only scalar opensearch attributes and keep credential source output out of 401s
* test(vector_stores): inject a failing opensearch credential source instead of running a shell
* fix(vector_stores): sign opensearch for the endpoint's region, refuse list, add opensearch_index_name, honor drop_params
* fix(vector_stores): refuse a caller-chosen opensearch_index_name on search and rag query
* fix(vector_stores): refuse opensearch_index_name only on OpenSearch stores, keep the old 400 text
Other providers drop the key again as they did before OpenSearch support, and the four embedding keys keep their original error sentence.
* fix(vector_stores): refuse a caller index on slash-form OpenSearch stores
77064d6c70