Sending an image/file renders the user message twice: the optimistic
bubble carries the raw caption while the backend persists an enriched
copy with "@image:" / "@file:" ref lines and a "[screenshot]" marker
(_build_image_ref_message / run_agent multipart flattening). The trimmed
exact-content compare in sameLogicalMessage fails on that drift and the
prefix fallback gate (>=40 chars) rejects short captions, so the REST
transcript sync appends the REST copy as a second bubble.
Compare USER rows on the caption with attachment-injection lines
stripped (stripAttachmentRefLines). USER-only so assistant text that
legitimately mentions these tokens is never collapsed.
Device-verified on the hermes37 emulator: image send + transcript
resync renders a single user bubble, restart/reload stays clean.
Unit: ChatToolDedupeTest 32/32.
M57
5153e1572f