Instead of calling openCommunicationThread() after sending (which triggered
a full timeline refetch, destroyed audio waveforms, and caused the chat to
jump), we now:
- Optimistically append the sent message to clientTimelineItems
- Scroll to bottom smoothly
- Refresh contacts sidebar for lastMessageText preview
- Auto-scroll only fires on thread switch (empty→loaded), not on every
timeline update, preserving audio waveform DOM elements
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
1a6840cdc6