resolveChannelStreamingPreviewToolProgress guessed a mode when streaming.mode
was unset, so it could never be right for every channel: guessing "partial"
dropped Discord and Telegram's explicit progress.toolProgress opt-out, and my
earlier switch to "progress" broke it the other way for Slack, Mattermost, and
Teams, whose real default is partial. With both keys configured and disagreeing,
the wrong one won.
The helper has no channel identity, so it stops guessing and takes the mode the
caller already resolved. All nine call sites pass theirs. Omitting it keeps the
previous configured-mode reading, so untouched callers behave exactly as before.
Reported by ClawSweeper on #116143.
c63241d3ce