Yuanbao's QuoteContextMiddleware has a transcript-lookup fallback for
when quote.desc is empty: it scans the session transcript for the quoted
message_id and pulls ybres anchors out of its content. That fallback
works for observed (silent) group messages because the platform writer
attaches message_id (yuanbao.py:2091).
It silently fails for @bot agent-processed messages because gateway/run.py
wrote them as {role:user, content, timestamp} with no message_id, so
quoting an earlier @bot turn that contained an image/file couldn't be
resolved.
Fix: attach event.message_id to the user transcript entry at all three
write sites in gateway/run.py — the agent_failed_early branch, the
no-new-messages edge case, and the normal agent path (first user-role
entry in new_messages).
Surfaces gap reported in #27425 (loongfay) using the existing fallback
already on main; no new caches needed.
Co-authored-by: loongfay <loongfay@users.noreply.github.com>
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