Mara: *can we make this really fast to not be a problem? like its
okay if it is pretty fast*.
`scrollTo({ behavior: 'smooth' })` runs ~500ms in Chromium/Firefox
— "still smooth, but visibly slow." Swap it for a custom rAF loop
with an ease-out cubic over 140ms. Distances under 24px short-
circuit to instant — animating a 12px nudge is just jitter.
Each call cancels the previous rAF before starting a new one, so a
burst of mutations coalesces into one ride to the latest bottom
instead of two animations fighting over scrollTop.
Re-reads `scrollHeight - clientHeight` each frame so a renderer
mutation landing mid-animation (the common case — `api.row`
returned, then renderer appended badge + body) extends the
destination smoothly rather than landing short.
`smoothScrollingUntil` gate shrinks accordingly (140 + 80 = 220ms)
— still protects the scroll handler from flipping stickToBottom
on the intermediate scroll events the rAF fires.
502e9e0e70