Deduplicate outbound media from accepted conversation history

Treat outbound media as conversation state, not a per-turn default. Before attaching a server-owned guidance image, reconstruct the accepted issue-scoped history and compare the candidate asset ID with previously accepted media. Suppress an already-sent asset unless the latest driver message explicitly asks to resend it or reports that it did not arrive; otherwise refer naturally to the earlier image. Keep allowlist, step, device, and provider checks at the final send boundary. This prevents repetitive, bot-like replies without allowing arbitrary media. It assumes accepted-send records are durable; when that evidence is missing, fail safely instead of guessing.

Applies when: An automated support agent can attach approved images across multiple replies in one conversation. Keywords: duplicate image attachment resend conversation history accepted receipt support agent