Feature: chat window ux tweaks

[jeremyeder]

1. Add timestamps for each chat message
2. Remove the new-line from between tool-calls. There is too much white-space. I want the tool-calls to look like this
   Before

Called Bash >
Called Bash >
Called Bash >
Called Edit > 
Called Edit > 
Called Read > 

After

Called Bash > (3) Called Edit (2) > Called Read >
``` .... and so on

3. Change chatbox font to monospace.
4. improve markdown rendering. make sure URLs are actually links that can be clicked.