Design an enterprise research agent with internal and web sources and citations

An employee asks a hard research question. Design the assistant that answers it by searching both the company's own systems (documents, wikis, a CRM such as Salesforce) and the public web, then writes an answer in which every claim points to the source it came from.

Cover how a question is broken into retrieval steps, how results from different sources are merged and ranked, how the answer is written and how its citations are checked, and how you keep people from seeing content they are not allowed to see. Say how you would measure answer quality.