[Bug]: Possible mismatch between texts and text_summaries in multimodal_rag_langchain.ipynb

### File Name gemini/use-cases/retrieval-augmented-generation/multimodal_rag_langchain.ipynb ### What happened? In the notebook `gemini/use-cases/retrieval-augmented-generation/multimodal_rag_langchain.ipynb`, there seems to be a mismatch between the IDs assigned to the original PDF chunks and the IDs used for the corresponding summaries. The code defines: doc_contents = texts + tables + img_base64_list doc_ids = [str(uuid.uuid4()) for _ in doc_contents] summary_docs = [ Document(page_content=s, metadata={id_key: doc_ids[i]}) for i, s in enumerate(text_summaries + table_summaries + image_summaries) ] However, `texts` (from `partition_pdf`) and `text_summaries` (after an additional split via `text_splitter.split_text`) do not necessarily have the same cardinality. ### Relevant log output ```shell Because `doc_ids` is generated from `doc_contents` and then indexed with `i` from `enumerate(text_summaries + table_summaries + image_summaries)`, any change in the number of chunks (e.g., due to re‑chunking with `text_splitter.split_text`) can shift the indices and cause summaries to be associated with the wrong original content. ``` ### Code of Conduct - [x] I agree to follow this project's Code of Conduct