Possibly related to #1360, but this appears to be a distinct remaining case.

When a long response is streaming, I can scroll to the top and read earlier lines. However, when the assistant finishes generating, the scroll position jumps to the bottom automatically.

Reproduction

1. Send a prompt that produces a long streamed response, for example:
   Reply with a 100 lines of random words. Add line numbers.
2. While the response is streaming, scroll to the top of the assistant message and keep reading there.
3. Wait for the response to fully complete.

Observed

As soon as generation completes, the viewport jumps to the end/bottom of the response.

Expected

If the user has manually scrolled away from the bottom, the UI should preserve scroll position when the stream completes.

Notes

• This feels related to bug(streaming): auto-scroll still overrides user scroll position on macOS app — #677 regression / edge case #1360, but the symptom is different:
  • bug(streaming): auto-scroll still overrides user scroll position on macOS app — #677 regression / edge case #1360: scroll snaps back during streaming
  • this report: scroll jumps when streaming finishes
• Reproducible with long multi-line outputs.
• I reproduced this with:
  Reply with a 100 lines of random words. Add line numbers.