The post-stream helper (_deliver_media_from_response) rescanned the
already-streamed response and promoted bare local filesystem paths into
real uploads via extract_local_files. Since the visible reply was already
streamed verbatim, any bare path there is either text the user has seen
or stale inspected/tool content — not an attachment request. On Slack this
uploaded images from stale inspected content after otherwise clean replies.
Post-stream delivery now honors only explicit MEDIA: directives. The
non-streaming path in gateway/platforms/base.py keeps its bare-path
auto-detect, because that path controls the visible text and strips the
path from the reply when it attaches — auto-attach is intentional there.
Regression tests: bare image/document paths in a streamed reply produce
no upload; explicit MEDIA: tags still deliver.
Fixes#20834
Teknium
4ab4894f44