[FEATURE]:Display timestamps on agent messages #190

Feature hasn't been suggested before.

• I have verified this feature I'm about to request hasn't been suggested before.

Describe the enhancement you want to request

It seems that even with time steps turned on, OpenCode only is displaying the times sent on user methods, not agent messages. It would be helpful if it was capable of displaying the time stamps on agent messages as well.

Let's add another option in the System group in the command palette to control the display of the timestamps on agent messages. Similarly to the existing command palette option for controlling the display of user message timestamps, it should be persistent to the kv.json file and it's name in the command palette should change according to its current state.