feat: pin team-posted comments to the top of the watch page

feat: sign posted comments with a random team member

feat: localise Hub Settings and ModelBanner

feat: localise the Watch flow and stop the player from auto-playing

feat: add comment composer recent activity feed and random usernames

feat: implement new models and improve UI, #23

fix: debug model selection, #22

feat: update UI using VITE+React without streamlit, #22