[BUG]: Chat Scrolling Broke when Streaming Responses were Introduced

[ericrallen]

Describe the bug:

When streaming responses were introduced, the scroll-to-bottom behavior of the chat window stopped working as expected due to the streaming response being updated as a separate prop and the scrolling logic being based on the overall conversation length, which only gets updated when the streaming response is complete.

The scrolling logic needs to take the streaming response into account and continue scrolling to the bottom while the streaming response is rendering.