My copilot persists the source cards it cites — which documents backed each answer, scores, names, the works. That's table stakes for a trustworthy RAG product: an answer without its evidence is just vibes. Here's the question that changed how I shipped it: six months from now, a user opens that old conversation and the cards render again. Who authorized them the second time? The comfortable answer is "nobody has to — it's the user's own history, they already saw it." I shipped the uncom...