Trimmed cherry-pick of PR #40592 (duration + dedup hunks only; the
voice-classification hunk duplicates #29235 and the send_voice Opus
rewrite is out of scope for this inbound-focused PR):
- adapter.py: ffprobe duration (off-loop) attached to Feishu voice
uploads via _build_file_upload_body(duration=...) and the audio
message payload (#16524, #8300)
- gateway/run.py: TTS dedup narrowed to the current turn;
_enrich_message_with_transcription dedups repeated audio paths
Refs #40592#16524#8300
seamusmore
d0c6353999