Many distinct reactions used to wrap into a tall stack (16 reactions =
4 rows at phone width). Now only the first row is shown, ending in a
"+N" chip; tapping it expands inline and a "less" chip collapses again.
Expanded state is remembered per message for the session. Nothing changes
when the reactions already fit on one row.
Overflowing chips stay in the DOM (invisible, aria-hidden, untabbable,
clipped by max-height) so the container keeps its natural width — which
keeps shrink-to-fit bubble layout stable — and each chip stays measurable.
utils/reactionOverflow.ts holds the unit-tested fit calculation; a
ResizeObserver re-fits on width changes. "+N" is forced LTR for RTL UIs.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA
