Personally I would argue that allowing users to install extensions, mostly adblockers, you remove what’s probably the single most common real world vector for attackers, ads. So while chromium browsers may be more secure I would say you’re probably less likely to run into a problem with a firefox based browser with ublock origin on it, mobile or desktop.
What you are looking for is a RAG and is one of the few legitimately useful implementations of LLMs outside the wall of hype.