chat-manager gains a chat:service-message lane (shared-secret auth via CHAT_SERVICE_SECRET) that posts on behalf of off-AC visitors with via: "youtube" + their display name — no activity feed, no push. The REST history surface and both laklok sisters carry the field through; televised messages render behind a red banner in raster and vector alike (parity 14/14). toolchain/tv/chat-bridge.mjs polls the active broadcast's live chat (quota-mannered, backlog-drained, flood-guarded) and forwards one way — the stream itself is the return path. Claude-Session: https://claude.ai/code/session_01EaVptJ3ZhyeQ9ZZZNcp55T