Support retrieving with just attributes filter without a query #30
Description
Currently, store.retrieve() requires a query string for semantic search. There are cases where you want to retrieve documents based solely on attribute filters without providing a search query.
For example, retrieving all documents from the last 7 days — without needing to specify a semantic search term.
The retrieve method should support being called with only an attributes_filter and no query (or an empty/None query), returning matching documents without ranking by embedding similarity.