When a streaming append/start call fails and chat.delete also fails, the
stream message is left in 'streaming' state — never finalized via
chat.stopStream, which may render as invisible or broken on mobile Slack.
streamSession.stopped is already set to true so the end-of-dispatch
finalizer also skips the stream, leaving the payload with no recovery path.
Remove the orphanDeleted guard from the deliverWithStreaming catch block:
always call deliverNormally here even if deletion failed, to ensure the user
receives the complete answer. A cosmetic duplicate on desktop clients is
preferable to a silently truncated answer.
The guard is intentionally kept in the finalizer catch: there the stream
message has already been fully finalized (all content visible), so skipping
deliverNormally on deletion failure avoids a true content duplicate.