The post-run scan that appends tool-emitted MEDIA: tags to the final
response iterated every tool/function message in the full conversation
and relied solely on path-based dedup against paths reconstructed from
the replayable transcript. When that reconstruction does not byte-match
the in-memory tool content (timestamp stripping, observed-context
withholding, compression rewrites), a stale path emitted several turns
earlier is absent from the dedup set and leaks onto a later text-only
reply (Telegram 'Sending media group of 1 photo(s)' with no MEDIA
directive present).
Scope the scan to this turn's new messages by slicing result['messages']
at len(agent_history) (agent_history is passed as conversation_history
into run_conversation, so the returned list is history + this turn).
Retain path-based dedup as a secondary guard and as the sole guard on
the compression-shrink fallback, preserving the #160 behaviour.
Closes#34608
08c0b22417