Implement a Simple RAG in a Notebook

Problem Overview You're working inside a Colab-style notebook that already contains a partially assembled retrieval-augmented generation (RAG) pipeline. Your task is to complete the missing cells. All the utility functions you need are pre-written, so you're filling in and adjusting code rather than building everything from scratch. The exercise is split into three stages: Embed: produce dense vector representations for a set of documents stored in a pandas DataFrame.…