Context: https://linear.app/comm/issue/ENG-761/spacing-regression-between-conversations-in-messagelist
Previous approach: https://phab.comm.dev/D3537
There was a regression with the MessageList component where the spacing between the conversationHeader (AKA timestamp) and messages was removed.
Went through the git history of chat-message-list.css and checked to see if any commits changed the div.conversationHeader CSS selector and found D3067 to be relevant. Specifically, the diff removed the padding property (I believe unintentionally).
I reintroduced the padding property, but set vertical padding to 6px instead of 7px to maintain the relationship with font-size (which went from 14px to 12px).