Feature request: add a "Regenerate" button to the chat response

[sogawa-sps]

Please consider adding a "Regenerate" button to allow users to regenerate the response if they are not satisfied with it.

If the user changes the model, the newly selected model should be used for regeneration.

It's not necessary to attach this button to the chat message and regenerate it inline as done in ChatGPT. For simplicity, it can be a separate button, and the new response can appear in a normal separate block.